KABUL: Afghan officials searched Friday for a member of a government-backed village defense force suspected of killing 11 civilians at a house in southern Afghanistan, officials said.

It was just one of several deadly attacks in the country, underlining the unstable situation as Nato scales back its operations, aiming to hand over responsibilities to Afghan security forces by the end of 2014.

Those killed in the Wednesday shooting in Khas Uruzgan district were members of Afghanistan's Pashtun majority, said Fareed Ayal, a spokesman for the Uruzgan provincial police.

The gunman is a member of the Hazara minority ethnic faction, Ayal said. The Taliban killed two Hazaras recently in the area because they were suspected of working for the US-led military coalition.

Police were investigating whether the latest killings were carried out in revenge.

Authorities said women and children were among the victims, but no other details were available.

Salim Assas, an Afghan National Police commander for several provinces in the south, said the gunman was a member of the Afghan Local Police, which is overseen by the Interior Ministry.

The Afghan Local Police program has been credited with providing security in areas where Afghan and Nato troops are not deployed.

However, Human Rights Watch issued a report last year alleging that some units were committing human rights abuses, including rape and murder.

In neighboring Helmand province, Taliban fighters attacked Afghan national policemen, killing one and wounding two others, said provincial spokesman Daoud Ahmadi.

Also Friday, in the east, 21 people were wounded when a bomb, which was placed in a canal that ran under a mosque, exploded in Chaparhar district, said Jamil Shamal, deputy police chief in Nangarhar province.