The tension over the cab-driving situation at Dulles International Airport heightened this week after a driver active in the movement to replace taxi-service operator Farouq Massoud was allegedly beaten by a driver sympathetic to Massoud.

The incident occurred Friday night in front of dozens of other drivers at the taxi staging area just north of the airport's main terminal. Witnesses said Babar Khan, 31, was chatting with other drivers when Ashiq Zubair, 39, approached, repeatedly challenged Khan to fight and then punched him in the face four or five times.

Khan said that after the cab dispatcher and an office manager refused to call authorities, he drove himself to the airport police station and reported the incident.

Airport police interviewed Zubair, who alleged that Khan had assaulted him. Both men were charged with assault and battery, an airport spokesman said, and face court hearings in Loudoun County on Oct. 12.

Neither man was seriously injured, officials said, but Khan said he suffered a bloody nose and a black eye.

Khan said that after the incident, Massoud, the exclusive provider of Washington Flyer cab service at Dulles, ordered him to take the next two days off, even though Khan had already paid Massoud the week's rent for his cab; Zubair was allowed to continue working, Khan said.

Neither Massoud nor Zubair returned telephone calls seeking comment.

Tara Hamilton, a spokeswoman for the Metropolitan Washington Airports Authority, confirmed that Khan appeared at the airport police station Friday night to report an incident, and that police issued summonses to Khan and Zubair.

The fight occurred one day before Khan was to host a fund-raising dinner for the Washington Flyer Taxi Drivers Association. Members of the group, formed in April after Massoud fired a number of drivers, say they have been trying to improve conditions for the 472 cabbies in Massoud's fleet at Dulles.

More than half the drivers rent cabs from Massoud, who holds an exclusive cab concession at the airport, at a rate of $475 to $500 a week; drivers also pay their own insurance costs of $3,000 to $4,000 a year. Drivers who own their cabs pay Massoud $140 a week.

The drivers association estimates that Massoud nets more than $5 million a year, while his cabbies must work seven days a week, 16 to 24 hours a day, to make a living.

The contract for the Dulles cab concession is now up for bid, and the drivers hope to wrest it from Massoud, who has held it since 1989. The deadline is Oct. 18 for new bids, which must include preliminary plans for constructing a new office for the drivers.

Khan and five other drivers, interviewed separately after Friday night's incident, said that Khan was sitting near a wooden platform called "the mosque" because Muslim drivers use it for their daily prayers to Mecca. The drivers said they saw Zubair park his car nearby, then walk quickly to Khan and grab his wrist and begin speaking loudly in Urdu, the native language of many of the drivers from Pakistan and Afghanistan.

"He kept saying to me, 'Do you have any problem with me? Do you have a joke with me?' " Khan said. Zubair repeatedly demanded, "Take your car outside and fight me," Kahn said.

When Khan stood up, he and the witnesses said, Zubair punched him once in the face. Liaquad Zaman, who was sitting next to Khan, said he tried to calm Zubair, then helped separate the two men.

Both began using "bad words," according to driver Shahid Shah, and then Zubair unleashed more blows. Some of those present said Khan tried to fight back but did not land any punches. Others said they did not see Khan fight back.

Khan said it was widely known that he was hosting a fund-raiser for the drivers association the next night. He said that Zubair is among those still loyal to Massoud and that the incident was staged to provide Massoud with a reason to fire him.

CAPTION: Driver Babar Khan, right, is active in the movement to replace Farouq Massoud, operator of the Washington Flyer taxi service at the airport.