A 64-year-old United Airlines passenger who had argued with the crew on his flight set his seat on fire at Dulles International Airport last night, officials said.

The incident was one of two unusual events at Washington area airports within about 15 minutes, on an evening of increased overall security because of the president's State of the Union address. A small plane coming from Atlanta reported smoke in its lavatory as it approached Reagan National Airport, but the flight landed without incident.

The Dulles passenger, who spoke Russian and little English, was belligerent at the gate before boarding Flight 383 for Chicago, said Transportation Security Administration spokeswoman Heather Rosenker.

Shortly after arriving at his seat, the man argued with a flight attendant, she said. Tom Sullivan, a spokesman for the Metropolitan Washington Airports Authority, said the man then used a lighter to set his seat aflame.

A flight attendant extinguished the fire, and federal air marshals on the plane stood by the man as the aircraft turned around and headed back to the terminal about 6:30 p.m., she said.

Passengers who saw the incident were questioned, and the flight was underway about 90 minutes later, Rosenker said. The flight later arrived safely in Chicago.

The marshals didn't have to subdue the man and did not identify themselves to the passengers, Rosenker said. The man was met by TSA officers, airport police and FBI agents at the terminal and was was arrested and charged with disturbing a flight crew, a federal offense, Rosenker said.

FBI agents said they believed the incident was "not terrorism-related," FBI spokeswoman Debra Weierman said. They did not immediately identify the suspect.

About 15 minutes before the Dulles incident, air traffic control at National Airport received the smoke alert from the small plane, Sullivan said.

Comair Flight 104 and its 19 passengers landed safely. Crews who searched the plane found no sign of smoke or malfunction, Sullivan said.