KABUL, Afghanistan (AP) — Taliban suicide bombers struck two buses carrying Afghan soldiers in Kabul early Wednesday, killing seven people and wounding 21, just a day after the signing of a key U.S.-Afghan security pact.

The long-awaited deal allows U.S. forces to remain in the country past the end of 2014, ending the uncertainty over the fate of foreign troops supporting Afghans as they take over the fight against the Taliban insurgency.