A Montreal woman who witnessed an alleged terror attack on board a Detroit-bound flight told CTV News Channel she feared an explosion as passengers frantically tried to subdue a suspect who had lit a fire in his lap.

"The flame was too high...smoke was coming, and we could feel the smoke," Shama Chopra said in a phone interview.

"I thought the plane was going to explode."

Chopra said Northwest Airlines Flight 253 from Amsterdam was about to land when she heard something that sounded like fireworks go off in the economy section, about five or six rows behind where she was sitting in business class.

"The fireworks started, and I turned my neck, opened my seatbelt, and see in the back the flight attendant was screaming: 'Fire! Fire!' and 'please give me the water!'" Chopra said.

"Everybody was running. Kids were screaming."

She said a passenger who was sitting behind the suspect jumped out of his seat and started putting out the flames.

"He just put it out with his hands," she said

While some passengers struggled with the suspect, the flight attendants and others gathered all the water bottles they could find and rushed to put out the growing flames.

She said four people managed to hold down the suspect. Umar Farouk Abdulmutallab, a 23-year-old Nigerian, has been charged. Authorities say he claims to have been acting on orders from al Qaeda.

"They hold this guy... and his shirt was taken off because it was burning. Then they bring him in the front where I was sitting, in the front of me," she said.

"But he was resisting. He doesn't want to sit. But they forced him to sit and they start screaming at him and they tie him with the rope," she said.

She said it was at this point she realized she had seen the man being held off to the side during security screening in Amsterdam. He had been sitting off to the side, deep in thought, with hands on his forehead. He had been held by guards before boarding, and was the last person to get on the plane.

Chopra said the entire incident happened about 12 minutes before the plane was about to land. The pilot came on the intercom to calm panicked passengers, but the frightening on-board battle between travellers and the suspect continued.

She said the captain assured passengers that the landing gear was in place and the plane was only 12 minutes away from landing.

The plane landed safely. The suspect was arrested and anti-terrorism officials are investigating claims that the suspect was given the explosive device and instructions in Yemen.

Now home in Montreal, Chopra still sounded frightened while recounting the incident.

"Somehow this device didn't explode," she said. "If it had exploded, we would be all gone. Finished. Two-hundred and-seventy-eight people, plus the crew," she said.