Many guests spent the night wrapped in blankets, waiting in hallways, lobbies and ballrooms. (Kenneth Benoit‏)

A series of suspicious fires early Saturday at the Washington Marriott Wardman Park hotel in Northwest forced guests from their rooms into smoky corridors and onto the grounds of the hotel in the pre-dawn darkness.

Guests said that at about 1 a.m., they were told to leave their rooms. One of them, Kenneth Benoit, said he left his 10th-floor room to find a corridor filled with smoke and people crowding fire-exit stairwells.

Benoit said he was allowed back into his room after several hours, only to have to leave when the fire alarm sounded again.

Many guests spent the night wrapped in sheets and blankets, waiting in hallways, lobbies and ballrooms, while firefighters searched the building.

The fires occurred in the midst of the annual meeting and exhibition of the American Political Science Association, a major gathering of 6,000 people at three Washington hotels and headquartered at the Marriott, in Woodley Park.

A hotel guest photographed the burned carpet in a hallway. (Kenneth Benoit‏)

“Late last night, we were alerted to a series of small fires throughout the hotel, primarily in stairwells,” hotel spokesman Mark Indre said. “As a matter of precaution, the guests were relocated from their rooms to ballrooms within the hotel.”

No injuries were reported. A D.C. fire department spokesman said the cause had not been determined. “It’s a little too early to say if it’s arson, but nothing is being ruled out,” the spokesman said.

Benoit, 46, a professor of political science at the London School of Economics, said he had been in bed only a short time when the alarm went off shortly before 1 a.m. telling guests to evacuate the building.

He wondered if it might be a drill.

“I woke myself out of my sleep stupor, managed to put my jeans and a shirt on and some shoes and socks,” he said. “As soon as I stepped in the hallway and I looked toward the fire exit, which is about eight doors down from my room, and the corridor was filled with smoke, I thought, ‘Okay, not a drill,’ ” he said in a telephone interview.

“I saw people coming out of their rooms and seeing the same shocked expression,” Benoit said.

“It appeared that the fire was either in the fire-exit stairwell or smoke was at least coming up through that,” he said.

Benoit said he went to another fire exit and found it crowded with people trying to get down. “It wasn’t moving at all,” he said.

He then found another exit and shouted to others to use it. “It was all very orderly and everything, but you do have a sense of urgency when you can see and smell smoke,” he said.

He made his way down to the lower level, then followed service corridors to an emergency exit.

“The hotel had been evacuated, and everyone was outside,” he said. Firetrucks arrived. “We had no idea what was happening.”

Two hours passed. After 3 a.m., he said, people were allowed back into the hotel and he returned to his room. Before going inside, he took some photos of a blackened carpet in the corridor and a singed fire door.

As he was about to Skype his wife in Germany, the fire alarm went off again. “I thought, ‘You’ve got to be kidding,’ ” he said.

Benoit said he milled about in the lobby and a ballroom with other guests until about 5:30 a.m. The hotel distributed sheets to guests. “The entire lobby looked like some sort of toga party,” he said.

There now seemed to be many more investigators as well as some police dogs. “They were clearly combing the building,” he said. “Some of the police were collecting samples of something in evidence canisters.”

He said word spread among the guests that a second fire had been started. “It could be an arsonist,” he said. “It could be a prankster.”

At 7:30 a.m., a hotel official announced that the building had been searched twice and that people would be allowed to return to their rooms, he said. He said the conference gradually got back to normal.