Obama hails police for anti-terror work

President Barack Obama praised the police department for its work in disrupting a possible terrorist bombing plot aimed at commuter trains.

Mr Obama dialled in to a briefing the New York Police Department was giving his counterterrorism and homeland security adviser to thank the police for their "outstanding" work during the UN General Assembly and the ongoing terrorism investigation.

He told the police they have the respect and gratitude of all Americans, White House press secretary Robert Gibbs said afterward.

"The president told the NYPD that he is particularly grateful for the exceptional teamwork that has been abundantly evident over the past several weeks with other police departments and with federal departments and agencies," Mr Gibbs said.

NYPD Commissioner Raymond Kelly and members of the NYPD's Intelligence Division and Counter Terrorism Bureau were briefing Obama adviser John Brennan on the ongoing investigation that led to the arrest of Najibullah Zazi, a Denver airport shuttle driver who's accused of conspiring to use weapons of mass destruction.

Zazi, an Afghan immigrant, had at least 18 bottles of peroxide-based hair lighteners and pages of notes for how to turn the beauty products into bombs, authorities say.

He has publicly proclaimed his innocence. His attorney says claims he planned an attack in New York City are missing a key element - explosives or the chemicals used to make them.

A recently unsealed criminal complaint had suggested that police acting without the FBI's knowledge might have compromised the investigation and helped blow the surveillance of Zazi by questioning a Muslim religious leader about him.

A top commander in the Intelligence Division was transferred after the investigation became public and concerns were raised about detectives' questioning of the Queens imam, who's accused of tipping off Zazi to the investigation.

The imam and Zazi's father face charges of lying to terrorism investigators; they deny the allegations.

Federal and NYPD investigators are seeking additional suspects. Authorities have issued a flurry of terrorism warnings for sports complexes, hotels and transit systems based on their investigation.