Thailand has imposed a state of emergency in its capital, Bangkok, and surrounding areas.

Thailand said today it would call in army reinforcements if necessary to assure the safety of 15 Asian heads of state in the face of mass street protests demanding the resignation of the government.t

Security forces tried to disrupt plots by al Qaida-linked militants to stage attacks but failed to track them, setting off an alarm that influenced a decision to postpone a pair of Asian summits, officials said today.