Gunshots fired by a member of the Taliban’s security forces at the United Nations’ largest compound killed one person and injured another in Kabul, the United Nations Assistance Mission in Afghanistan (UNAMA) said in a statement on Monday.

The incident took place on Sunday, it said.

The person killed was a member of the Taliban-run security forces who was outside the compound, the statement said without adding any details.

The person injured was an international security guard contracted by the UN, it said.

“UN-contracted security guards did not return fire during the incident,” it said.

It was unclear what provoked the firing. Both the Taliban and the UN were investigating the incident.

Kabul’s interior ministry spokesperson Abdul Mateen Qaniee confirmed that a Taliban guard was killed and one UN contractor suffered injuries.

Taliban authorities halted all movement in and out of the compound following the incident, UNAMA said, but those restrictions have now been lifted.

The compound houses the offices of multiple UN agencies, funds and programmes, and accommodation for UN international staff members.