A Philadelphia congressman was charged last night with assault and battery in connection with a brawl that allegedly broke out early Tuesday in the rooftop bar of an Arlington hotel, Arlington police reported.

Rep. Michael O. Myers (D-Pa.) is accused in two separate warrants for assault and battery of a security guard and a cashier, both of whom were treated for minor injuries, according to police.

A police spokesman said Myers' office will be notified of the warrants, but, since the charge is a misdemeanor punishable by no more than a $1,000 fine and/or a year in jail, no effort will made to arrest the congressman outside Virginia. The warrants will be served if Myers comes into the state, he said. Myers has no Washington area residence and commutes to Congress from Philadelphia.

Myers denied taking part in the incident that allegedly began in the revolving Skydome Lounge on the 15th floor of the Pentagon City Quality Inn about 1 a.m. Tuesday.

"I saw a little pushing and shoving getting into an elevator, but I didn't see no fight," said Myers, who added that he heard the trouble began when a waitress threw a handful of matches at the group.

Myers said he left the hotel before police arrived. Arlington police said they obtained a warrant for his arrest lash night after several witnesses identified him from a picture as one of the participants in the incidents.

The warrants charge him with assaulting security guard Michael Loper and cashier Kimberly Ervin.

John L. Sullivan, identified by a Myers aide as the congressman's cousin, was charged Tuesday with assault on Loper and Ervin and with public drunkenness. A police report says Sullivan "pulled his trousers and undershorts down to his knees" while being led from the hotel by police.

According to police, Myers and more than a dozen companions began creating a disturbance in the lounge some time after 10 p.m. Monday, ignoring requests by hotel employes to lower their voices.

A man who "Identified himself to the employes as Congressman Myers stated because he was a congressman he did not have to abide by their rules," a police report said.

Police said that at closing time several members of the group, including Sullivan and Myers, dragged Loper into an elevator and kicked and punched him to the elevator floor. Ervin also was kicked and punched, police said, when she went to Loper's aid.

"I understand some of my crew was out there," Myers said Tuesday when asked about the incident, which followed a Monday afternoon cocktail party for 400 of his constitutents on Capitol Hill. Later he conceded, "I was out there for a while." Myers, 35, a former longshoreman, was registered at the hotel but said he slept in his congressional office.

Sullivan, who gave a New Jersey address, was released Tuesday morning on $275 bond.

Myers succeeded the late Rep. William A. Barrett in Pennsylvania's 1st Congressional District in 1976.