Britain ordered its military on Tuesday to stop using cluster bombs that lack self-destruct mechanisms in a decision intended to prevent the weapons — used as recently as the beginning of the Iraq war — from harming civilians.

Defense Secretary Des Browne said the weapons, also known as dumb cluster bombs, would be withdrawn immediately from Britain's arsenal and destroyed.

"This decision is part of our wider efforts to reduce civilian casualties and to press other militaries to do the same," Browne told lawmakers in a written statement.

Cluster bombs are shot from artillery or rocket ground systems, or dropped from aircraft, and disperse hundreds of smaller munitions, known as bomblets. Unexploded bomblets can lie dormant for years until they are disturbed, often by children.

In February in Norway, 46 countries adopted the groundwork for an international treaty banning the munitions, but some of the biggest makers and users of cluster bombs — the United States, Russia, Israel and China — didn't attend the conference.

The Oslo Declaration urged nations to "prohibit the use, production, transfer and stockpiling of those cluster munitions that cause unacceptable harm to civilians."

The British government will be withdrawing more than 46,000 rockets and cluster munitions under the order.

The British military will continue to use the so-called smart cluster bombs, which have the capacity to self-destruct, Browne's statement said, calling them legitimate weapons with significant military value.

Tom Nash, the coordinator of the Cluster Munitions Coalition campaign group, said the decision to keep the smart bombs in the arsenal was worrying.

"Just as a bomblet can fail, a self-destructing mechanism can fail," Nash said.