Afghan authorities say two suicide bombers have killed three people and wounded eight in the southern city of Kandahar.

One of the attackers killed a former factional commander, Agha Shah, and two bystanders outside Agha Shah's house.

Later, a second bomber blew himself up, but caused no other casualties, when police ordered him to stop near the main U.S. military base in Kandahar.

There have been two other suicide bombings in the Afghan city in less than a week, one against British officials and the other targeting Canadian troops.

Meanwhile, the U.S. military says an American soldier was killed and another wounded Sunday during fighting with insurgents in Zabul province.

Separately, a U.S. military helicopter made a hard landing and caught fire during an anti-militant operation in eastern Afghanistan. The helicopter was destroyed, but all onboard escaped unhurt.