WASHINGTON, Nov 18 (AFP) - Independent US senator Joe Lieberman on Wednesday called this month's deadly shooting spree at the Fort Hood army base "the most destructive terrorist attack on America since September 11, 2001."

Speaking at a meeting of the US Senate Homeland Security Committee, Lieberman, who chairs the panel, vowed to conduct a thorough probe of the shooting -- one of several planned by the US military and government officials.

"We appreciate that the army and the Justice Department are conducting a criminal investigation of the shooting," said Lieberman, also noting a separate probe ordered by President Barack Obama.

"I support those investigations look forward to their outcomes," he told reporters, but said nonetheless that this committee has launched its own probe "to determine whether the federal government could have prevented the murders at Fort Hood."

The top Republican on the homeland security committee, Senator Susan Collins said at the same press briefing that the massacre at the US army base "raises questions about whether there are unnecessary restrictions on information sharing" among law enforcement and intelligence agencies.

"We have the obligation at the Homeland Security (committee) to ask the tough questions," Collins said.

Various experts were due to testify at a hearing of the panel Thursday including General John Keane, retired former vice chief of staff of the United States Army; Frances Townsend, ex-White House homeland security adviser; and Mitchell Silber, director of analysis at the Intelligence Division of the New York City Police Department.

The November 5 rampage, allegedly by army psychiatrist Major Nidal Malik Hasan, killed 13 people and wounded another 42.