British use of cluster bombs in the Iraq war could count as a war crime and justifies further investigation by the International Criminal Court (ICC) prosecutor in the Hague, a group of international lawyers say.

Seven academics from Britain, Ireland, France and Canada interviewed eyewitnesses and examined evidence to see if there was a case for referring British conduct to the court, said the pressure group Peacerights, which organised the review.

"There is a considerable amount of evidence of disproportionate use of force causing civilian casualties," one of the lawyers, Professor Bill Bowring of London Metropolitan University, told a news conference on Tuesday.

"The U.S. cannot be tried before the court because it refuses to sign up to it. The UK did."

Cluster munitions are small bomblets scattered on a target area by larger bombs, rockets or artillery shells, designed to destroy infantry or soft skinned vehicles.

Use of bunker-busting munitions had also killed civilians, Peacerights said.

"THIS ONE GOES TO TOP"

ICC officials were unavailable to comment, but Bowring said senior politicians, possibly including Prime Minister Tony Blair, could have something to worry about.

"Heads of state are not immune in principle," the law professor said. "This one goes right to the top."