TRIPOLI, Libya — As rebels inside Tripoli said they were advancing toward ruler Moammar Gadhafi’s compound Sunday, the defiant leader called on Libyans to stop “colonizers” from taking over the nation’s capital.

“I am with you in this fight. We will not give up,” he said in audio remarks broadcast on Libyan state television.

“The colonizers are trying to colonize the city of Tripoli, so they come with their army to invade our beloved Libya,” he said, “but we will not allow them to do so until the last blood drops from every man and woman.”

Gadhafi’s remarks came as gunfire crackled and explosions rocked Tripoli, and government officials reported that more than 370 people had been killed in the past day of clashes.

A fierce gun battle broke out Sunday evening near the hotel where many international reporters were stationed in Tripoli. Many government officials packed their suitcases and left the hotel earlier Sunday.

Nearly 1,000 people were wounded in fighting that began Saturday night, a Libyan government official said, and 376 were killed. Officials did not provide further details about the casualties.

Libya’s government spokesman vowed that loyalist soldiers and volunteers would fend off attacks.

“Tripoli is well-protected, with thousands upon thousands ready to defend the city against any invasion,” government spokesman Musa Ibrahim told reporters Sunday.

“They wholeheartedly believe that if this city is captured, the blood will run everywhere, so they may as well fight until the end,” he said.

Saif al-Islam Gadhafi, a son of the ruler and a top official in his regime, said earlier on state television that the rebels were losing every battle. His statement came hours after his father told supporters that the “traitors” and their NATO allies were lying and nearing their end.

The Gadhafis’ accounts, however, contrasted with reports from CNN reporters, witnesses and rebel officials that government forces continued to lose ground across the North African nation and faced fresh attacks in the capital.

Rebels moved truckloads of ammunition on roads toward Tripoli on Sunday after seizing an ammunition depot previously held by Gadhafi’s forces. After claiming victory in Zawiya — about 30 miles west of Tripoli — a group of rebel forces said they were continuing their march east and closing in on the capital.

Some areas of eastern Tripoli — including the suburb of Tajoura — were out of government control Sunday, according to a Libyan government official who asked not to be named.

Rebels had set car tires afire along barricades there, the official said.

The official said 65,000 troops loyal to Gadhafi were ready to defend Tripoli, and warned that a massacre would occur if NATO continued to back rebel efforts.

Faithi Baja, political affairs chief for the rebels’ Transitional National Council, said in a video statement Sunday that the rebel fighters’ freshly launched operation inside Tripoli was “going easily” and that they were inching toward Gadhafi’s Bab al-Azizia compound.

“Most of the neighborhoods in Tripoli are rising up,” said Jumma Ibrahim, a rebel spokesman from the western mountain region around Zintan. He also said Libyan rebels took control of the city of Jaddaim, west of Tripoli, on Saturday night.

The rebel spokesman claimed opposition fighters had taken control of the main intelligence operations building in Tripoli. He also said some Libyan army personnel had defected and joined the rebels in the area of the capital’s airport, which he claimed the rebels took over.

But the government spokesman denied that the airport had switched hands, insisting all of Tripoli was safe and under the control of Gadhafi’s forces.

CNN could not immediately confirm whether rebel fighters had taken control of any parts of the city, including the airport.

Gunfire and explosions have been common in the capital, but a CNN crew on the ground for weeks reports that this weekend’s fighting appears to be among the most intense yet.

Heavy clashes erupted Saturday night in at least one Tripoli neighborhood, marked by intense gunfire, explosions and people screaming as they ran through the street, a resident told CNN.

On Sunday morning, several fires were burning in eastern Tripoli.

The Libyan government spokesman appealed for a cease-fire Sunday and called on NATO to stop its campaign.

“Every drop of Libyan blood shed by these rebels is the responsibility of the western world, especially NATO’s countries. We hold (U.S. President Barack) Obama, (British Prime Minister David) Cameron and (French President Nicolas) Sarkozy morally responsible for every single unnecessary death that takes place in this country,” said Musa Ibrahim.

NATO, working under a U.N. Security Council resolution authorizing the use of force to protect Libyan civilians, has conducted 7,459 strike sorties in Libya since the end of March, the alliance said Sunday. It made 22 “key hits” in the Tripoli area Saturday, including on several military facilities.

Officials briefed Obama on the situation in Libya on Sunday morning and the president will continue to receive updates, White House spokesman Josh Earnest said.

“We believe that Gadhafi’s days are numbered, and that the Libyan people deserve a just, democratic and peaceful future,” Earnest said.

A senior Obama administration official said Sunday that Gadhafi’s “already limited options (would) become even more limited” if Tripoli falls to rebels.

“Anti-Gadhafi forces have had momentum on their side for some time,” the official said. “What we’re seeing is further evidence of their sustained persistence.”

U.S. Sen. John McCain, R-Arizona and ranking member of the Senate’s armed services committee, said it was “a matter of hours if not days” before Gadhafi leaves power.

“I believe that it’s nearing the end,” he told the CBS program “Face the Nation” on Sunday.

As clashes appeared to intensify Sunday, a Maltese ship seeking to evacuate foreign nationals from Libya came under heavy fire as it attempted to dock at the Tripoli port.

A rebel-controlled ship ambushed the ship’s crew and passengers near the Libyan coastline in what appeared to be a hijack attempt. As the captain tried to steer toward the port, Gadhafi forces began firing at the rebels, leaving the Maltese ship in the crossfire.

No injuries were reported, but the ship was forced to turn around, with its crew fearing for the safety of those onboard. The foreign nationals remained stranded in Libya.

Gadhafi, meanwhile, claimed rebel officials were lying about the situation in Tripoli and beyond. He said the six-month-long conflict would climax soon.

In an audio address broadcast on state-run TV, the Libyan leader blasted the rebel “traitors” and the NATO forces backing them as unethical and intent on destroying the county and ruining lives. And as he had done in a speech six days earlier, he tried to rally citizens to his side.

“March forward, march forward, march forward. They have lost and used everything, and their last resort is their lying campaign. Now, this is the ending,” he said.

About 30 miles west of Tripoli, thick plumes of smoke hung over the sky Sunday as multiple loud explosions rocked the city of Zawiya.

Rebel fighters told CNN they controlled Zawiya and had pushed Gadhafi’s forces 15 miles outside the city, moving that battle’s frontline closer to Tripoli. But Gadhafi’s forces continued firing into Zawiya from a distance.

Rebel forces also said they controlled a major oil refinery and cut off a key coastal road outside the city — a major supply route to the capital.

Libyan state television reported Sunday that dozens of armed rebels were arrested south of Zawiya, and their weapons were seized.

Rebel fighters told CNN Saturday that NATO had warned civilians to leave the main part of the city. NATO has not yet commented on that statement.

As for the capital, Saif al-Islam Gadhafi laughed at the notion that the opposition would take Tripoli. And he was emphatic that he, his father and their supporters would not surrender.

“We are in our land, in our country,” he said. “We have no problem if it takes six months, one year or two years — victory will be ours. This is our country, and we will not leave it.”