The operator of the Minneapolis-St. Paul International Airport on Monday approved tougher penalties for cabdrivers who refuse service to travelers carrying alcohol — a policy that will affect hundreds of Muslim drivers.

On a unanimous voice vote, the Metropolitan Airports Commission agreed to rules that will suspend a driver's airport taxi license for 30 days the first time the driver refuses service and revoke the license for two years after the second violation. The new penalties take effect May 11.

Commissioners hope the rules will end an issue simmering for the past several years.

More than 70 percent of the cabbies at the airport are Somalis — who are commonly Muslim — and many of them claim that Islamic law prohibits them from giving rides to people carrying alcohol.

Under the airport's old rules, a driver who refused to transport someone carrying alcohol would be told to go to the back of the taxicab line. Since January 2002, there have been more than 4,800 instances of a driver refusing service because a customer possessed, or was suspected of possessing, alcohol, airport officials said.

Commissioners said the old rules didn't prevent customers from being stranded at the curb or — as reported in a few cases — dropped off before their destination after drivers learned of their alcohol on board.

"It's not an issue that's easily resolved," Metropolitan Airports Commission chairman Jack Lanners said before the vote. "In the end, we need to make a decision that deals with the most important issue, which may deal with consumers and their right to customer service."

Some Somalis who testified Monday urged commissioners to reject the new penalties and find some other solution.

"We see this as a penalty against a group of Americans only for practicing their faith," said Hassan Mohamud, an imam — or Islamic religious leader — and an adjunct professor at William Mitchell College of Law.

Jeffrey Hassan, a lawyer who represents Muslim cab drivers, said a reasonable accommodation between Muslims and the public could be reached but that none have been tried.

An earlier proposal floated by the commission would have had drivers against alcohol display a different top light on their cab. But the idea was canned after a public backlash, and some other taxi drivers said they feared it would make travelers avoid taxis altogether.

The airport dispute is one of several in Minnesota involving Islam and the public sphere.

Some blind airport passengers have complained that Muslim cabbies won't pick them up because they believe their guide dogs are unclean. Six imams are suing US Airways after they were removed from a flight in Minneapolis when passengers reported suspicious behavior. And some Target Stores in the Twin Cities have reassigned cashiers who were refusing to scan pork products because of Islam's prohibition against pork.

At the airport Monday, cab driver Abdinoor Dolal said the situation could be solved by simply letting cabbies who refuse service stay in line while customers are directed to other drivers. He said the inconvenience would be minimal.

"I get my rights and I get to stay in line, and the customer gets their rights," he said.

But commissioners said they weighed the religious arguments and ultimately decided the penalties were needed to ensure that customers would get safe and reliable taxi service at the airport.

"We have been talking about this for a year now and haven't found an accommodation that suits everybody," airport spokesman Pat Hogan said.