KABUL, Afghanistan — 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.

Wednesday’s attacks involved two suicide bombers targeting buses carrying Afghan troops in the country’s capital.

The first attacker hit a bus with Afghan National Army officers in west Kabul, killing seven and wounding 15, said the city’s criminal investigation police chief Mohammad Farid Afzali.

The second attacker, who was also on foot, blew himself up in front of a bus in northeastern Kabul, wounding at least six army personnel, Afzali said.

Taliban spokesman Zabihullah Mujahid claimed responsibility for the attacks, saying the security pact with America has only motivated the group and given the Taliban “more morale” to fight the enemy.

“They need to give more sacrifices to make their homeland free,” Mujahid said, referring to Taliban fighters.

In a separate statement to media, the Taliban denounced the Bilateral Security Agreement as an “American plot” and said that “such fake documents will never hold back the lawful jihad,” or holy war.