ISLAMABAD - A suicide blast in a former militant stronghold in northwestern Pakistan has killed at least 11 soldiers, including one officer, and injured 13 others.

The attack took place Saturday night in an area in the scenic Swat Valley where army officers conduct sporting activities, said an official statement. It gave no further details.

Sources told VOA army officials were playing in a volleyball match when the bomb went off.

A spokesman for the outlawed Pakistani Taliban swiftly claimed responsibility, saying the attack inflicted heavy casualties, though militant casualty tolls are often inflated.

Swat used to be a stronghold of the Pakistani Taliban until 2009 when the army launched a major counterinsurgency offensive and flushed militants from the valley.

Since then peace has returned to the area popular with domestic and foreign tourists, and militant attacks have become extremely rare in the valley known as Pakistan's Switzerland.

