3 American troops die in Afghanistan

Three Americans and two other foreign troops were killed Friday in an attack in eastern Afghanistan, officials said.

Insurgents attacked Afghan and coalition forces with grenade launchers and guns, NATO forces said in a statement. The troops called in air support, and the militants withdrew. They are being pursued, the military said.

Col. Greg Julian, a spokesman for U.S. Forces in Afghanistan, confirmed that three of the slain troops were Americans. The nationalities of the other two were not immediately known because the North Atlantic Treaty Organization typically waits for countries to release such information.

The Taliban has vowed to increase attacks as an additional 21,000 U.S. troops enter Afghanistan this summer in an attempt to stem the group’s resurgence and bolster security for August presidential vote.

In a sign that electioneering itself is likely to be chaotic, Afghanistan’s top vice president broke away from the president to join a competing ticket, a spokesman for the ticket said Friday.

First Vice President Ahmad Zia Masood joins former warlord Gul Agha Sherzai as his top deputy, said Gul Khalid Pushtoon, a lawmaker serving as spokesman for Sherzai.

Sherzai, governor of eastern Nangarhar province, plans to file official papers today to run against President Hamid Karzai, Pushtoon said.

A government spokesman, Waheed Omar, said he had not yet been informed of Masood’s decision but that the government wouldn’t stand in his way.

Three Afghan army soldiers and 15 militants also died Friday in clashes in the south and east, U.S. military and Afghan officials said. No coalition casualties were reported in those incidents.