Bagram Air Base attack leaves four Americans dead

Four American service members were killed in a mortar attack at Bagram Air Base outside of Kabul Tuesday, shortly after the announcement of the first-ever talks between the U.S. and Taliban representatives.

The Taliban claimed responsibility for the attack.

The four Americans were members of the International Security Assistance Force serving in eastern Afghanistan, the ISAF said.

The U.S. also handed over security responsibilities to the Afghan government Tuesday, even as violence escalated throughout the conflict-ridden nation.

A bomb hit western Kabul Tuesday, killing three civillians, and last week, the Taliban claimed responsibility for an attack on the Kabul Supreme Court that killed at least 16 people.

Afghan President Hamid Karzai said Tuesday he would suspend security talks with the U.S. in protest of the outreach to the Taliban.