Afghan injured children are treated at hospital in Helmand province, south of Kabul, Afghanistan, Wednesday, Dec. 31, 2014. A rocket fired amid fighting between Taliban insurgents and Afghan soldiers killed at least 26 people at a nearby wedding party Thursday night, authorities said, a grim end to a year that saw the end of the 13-year U.S.-led combat mission there. (AP Photo/Abdul Khaliq)

KANDAHAR, Afghanistan - Two Afghan soldiers have been arrested in connection with the deaths of at least 28 people, mostly women and children, who were killed by artillery fired from military checkpoints at a wedding party, an official said Friday.

Gen. Sultan Mahmoud, the head of the army in southern Helmand province, where the incident took place on Wednesday night, said the soldiers were arrested late on Friday. Another eight soldiers were still under investigation, he told The Associated Press.

"There is still a possibility of more arrests because the investigation is not over yet but those who were directly involved have been arrested today," he said.

Investigators sent from Kabul by the Defence Ministry arrived in Helmand's capital of Lashkar Gah earlier in the day, Gen. Dawlat Waziri, deputy Defence Ministry spokesman said.

An initial probe found soldiers had fired at a house from two directions while the wedding party was in full swing in the volatile district of Sangin, in the poppy-producing Helmand River valley.

Officials in the province earlier said that the artillery fire wounded at least 51 people at the house in the Sarwankhala area of Sangin, where government forces and Taliban insurgents have fought skirmishes for the last six months since U.S. forces withdrew.

Mahmoud said all soldiers in the area at the time of the incident had been confined to their base until the investigation concludes.

About 300 people travelled from Sangin to the provincial capital of Helmand, 85 kilometres (52 miles) away to protest outside the home of the governor and demand justice for the dead.

The incident happened just hours before Afghanistan's own forces took control Thursday of nationwide security after the end of the 13-year international combat mission led by the United States and NATO.

Fighting continues across the country, however, as Taliban insurgents test the capacity of the Afghan forces, trained mainly by the U.S. military but now operating largely without their help.

Earlier Friday in Lashkar Gah three employees of the private Azizi Bank and a policeman where killed when a roadside bomb exploded beneath a bank vehicle, said Omar Zwak, the spokesman for the provincial governor.

News from © The Associated Press, 2015