SAO PAULO, Brazil (CNN) — Gas pumps in Sao Paulo, Brazil’s biggest city and financial capital, were running dry Wednesday due to a truckers strike that began two days ago.

A state court ruled late Tuesday that the strikers must go back to work, but according to radio stations that monitor traffic, many gas stations’ tanks were still empty Wednesday.

“The strike movement carried out by members of the unions is compromising the supply of vehicular fuel in gas stations, which is generating insecurity in citizens of São Paulo,” wrote Judge Emilio Migliano Neto. Unions participating in the strike could be charged up to $1 million reais ($568,828) per continued day of strike.

The Retail of Petroleum Products for the State of Sao Paulo Union (Sincopetro) reported that by Tuesday evening, at least 50 fuel stations were completely out of gasoline, ethanol and diesel. Another 31 stations had no ethanol and 35 stations no longer had diesel fuel for sale.

The capital has about 2,000 fuel stations.

Truckers declared a strike against new driving restrictions in the city of Sao Paulo that prevent them from using many central streets and arteries during peak hours.

In Sao Paulo, a city of 11 million people and 7 million vehicles, traffic congestion is notorious.

“We’ve been out of gas since (Tuesday),” said one gas station attendant. “We don’t know when we’ll get more.”

Jose Alberto Paiva Gouvea, president of Sincopetro, said in a radio interview that it could take four or five days to refill the city’s gas stations.

Taxis, which run on natural gas provided through pipelines, were not affected, and some taxi drivers expect business to pick up if the shortage lingers.

Meanwhile, motorists are left with few choices.

“What can I do? I’m going to have to go to work and leave my motorcycle there because I don’t have enough gas to get home,” said a motorcycle rider named Guilherme.

— CNN’s Marilia Brocchetto contributed to this report.