LONDON - Two British soldiers have been killed in separate incidents in southern Afghanistan, the Ministry of Defence said on Sunday.

One soldier was killed in a rocket propelled grenade attack and the other by a contact explosion near Gereshk, Helmand Province, on Saturday evening, it said.

The deaths raise to 173 the number of British troops to have died since Britain joined the United States and other countries in invading Afghanistan in 2001.

Thousands of U.S. and British forces launched a large-scale operation across southern Afghanistan earlier this week to try to drive the Taliban back and retake territory.