U.S. authorities are considering ways to tighten security in public areas at U.S. airports after a deadly attack in Moscow last month, John Pistole, the head of the U.S. Transportation Security Administration, said.

A suicide bomber last month killed 36 people and injured more than 100 after detonating the device in the international arrivals hall of Moscow's busy Domodedovo airport, sending airport officials scrambling to address the security gap.

Pistole told U.S. lawmakers he had submitted ideas to Homeland Security Secretary Janet Napolitano on how to improve security in locations passengers go through before being screened for flights, a job usually handled by local police.

The ideas included checkpoints before vehicles are allowed to pull up to the airport terminals, small security teams patrolling the grounds and using officers who are trained to detect unusual behavior, he told a House of Representatives' subcommittee on transportation security.

U.S. authorities have ramped up security for air travelers, luggage and cargo in the wake of several attempts by al Qaeda militants to attack the United States, adding full-body scanners and requiring more screening for cargo. (Reuters)