The operator of the Minneapolis-St. Paul International Airport moved closer on Monday to approving penalties for cab drivers who refuse service to customers carrying alcohol, as some Muslim drivers have done for religious reasons. The panel of the Metropolitan Airports Commission voted to suspend a driver's airport taxi license for 30 days for the first offense and revoke it for two years for a second offense. Commissioner Mike Landy said the entire commission was to vote on the penalties later Wednesday. The issue went before went before the panel after a months-long dispute in which passengers said they were being denied taxi service by some Muslim drivers if they were transporting alcohol. Minneapolis-St. Paul International Airport officials say more than 70 percent of the cab drivers at the airport are Muslim. The drivers, however, have argued that Islam forbids the carrying of alcohol. In the months before the decision to consider stiffer penalties, the commission proposed a compromise that would have let Muslim drivers display a different-colored light on their cab if they did not want to pick up passengers carrying alcohol. But that proposal triggered a huge backlash, from both passengers and other taxi drivers who feared it would make travelers avoid taxis altogether. Cab driver Abdinoor Dolal called the penalties punitive and asked commissioners to take a measured approach.