In national news tonight....A Nigerian man is in custody... accused of trying to blow up a Northwest Airlines flight that landed in Detroit today.Federal officials say the man claims he's acting on behalf of al Qaida and his name is on the national terror data base.CBS News Correspondent Thomas Roberts has the latest.Federal officials say Northwest Flight 253 was just about to land in Detroit when a man onboard tried to light a mix of explosive powder and liquid."We heard a loud pop and a bit of smoke and then some flames and then yelling and screaming.""There was a fire in the plane after a few seconds, it was very scary for everyone."Officials say passengers tackled the man and may have prevented him from detonating the explosives...allowing the plane to land safely."He jumped over all the other people and he took care of it so the fire went out."Authorities arrested a badly burned 23-year-old Umar Farouk Abdulmutallab from Nigeria.Dawn Griffith/Husband on Flight says,"His hands were wrapped in bandages and handcuffed to the railing of the (inaudible)."Immediately, a bomb squad went to work, making sure no other explosives were on the plane. President Obama is calling it an attempted act of terrorism and he's asked for increased airline security...including additional screening for passengers.The Northwest flight used a Delta plane...originating in Nigeria and making a stop-over in Amsterdam. 278 passengers were on board. Officials say Abdulmutallab should NOT have been one of them because he is on the national terror watch list...he is known to have terrorist connections. He says he's working for al Qaida, but officials have not confirmed that. They say the attack does not appear well-planned and they think he acted alone. He's now in F-B-I custody. Thomas Roberts for CBS News, Los Angeles.