KABUL — Officials in Afghanistan said on Sunday they were investigating claims that at least nine civilians, including six children, had been killed when Afghan and coalition forces blew up a Taliban weapons depot in southern Helmand province.

Omar Zwak, a spokesman for the governor of Helmand, said that troops on a military operation in the Malgir area of Gereshk district, just outside the provincial capital of Lashkar Gah, had found the cache of munitions late Saturday.

“They set up explosives to detonate the cache, and it damaged the house where the civilians were staying,’’ Zwak said.

Captain Bill Salvin, a spokesman for the coalition in Afghanistan, said Sunday that the reports would be investigated.

General Dawlat Waziri, a spokesman for the Afghan Defense Ministry, said a team had been sent to Helmand to look into the claims.

The owner of the house that collapsed, Haji Mohammed Sadiq, said it was being used by a family that had been taking care of his farm for him since he moved to Lashkar Gah to escape the fighting. The concrete building next door housed a clinic before the Taliban moved in, Sadiq said.

“Last night, Afghan forces, along with foreign forces, raided the clinic around 11:30 p.m., and arrested some 40 to 50 villagers, and took them to the desert, and only left women and children in the houses,’’ he said. “They put explosives over the clinic and detonated it, and the mud house next to the clinic collapsed.’’

Civilians have continued to bear the brunt of much of the violence from both sides amid the intensifying conflict in Helmand, with many repeatedly displaced by the fighting.