Twenty-one Egyptian policemen were killed in a road accident Monday as their driver lost control of their truck in the Sinai, where security forces are battling extremist militants.

Twenty-one Egyptian policemen were killed in a road accident Monday as their driver lost control of their truck in the Sinai, where security forces are battling extremist militants, the Egyptian interior ministry said.

Twenty-four policemen were injured in the accident near the border with the Occupied Palestine, it added in a statement.

The dead and injured conscripts belonged to the interior ministry's Central Security Forces, which along with the army has been battling extremist militants behind a series of deadly attacks in the lawless peninsula.

In a separate incident, another policeman and a gunman were killed in a gunfight in the northern Sinai town of El-Arish during a foiled attempt to rob a postal vehicle carrying money, security officials said.

They said the firefight was unrelated to militant attacks in the region that have targeted police and soldiers, including a brazen August 5 ambush on an army outpost that killed 16 soldiers.

The military launched an unprecedented operation involving tanks and helicopters to quell the militants after the August 5 attack, which also led to the sacking of top military generals and the head of intelligence.

Security in the desert and mountainous region had collapsed after a January-February 2011 uprising that forced former president Hosni Mubarak to step down.