Four children aged between 9 and 12 in a mountainous area in the central province of Thanh Hoa were killed when a wall at an excavation site collapsed on them on Saturday.

All of the dead victims were from Quang Trung commune, Ngoc Lac mountainous district.

Bui Thi Lan, a local woman in Ram village in Quang Trung commune, hired an excavator that morning to dig up earth on her land to build a new house to run a shop, according to Pham Hung Thu, deputy chairman of Ngoc Lac District.

Thu said the deadly incident occurred as the four children sat under the shadow of a wall to avoid the sun. But the wall accidentally collapsed and immediately killed two of them. The two others died on the way to hospital.

It is believed that the wall collapsed because its base weakened after the sand underneath was excavated. 

Families of the dead victims were given a financial assistance of VND4.5 million (US$213) each to arrange funeral services for them.

Further investigations into this care are underway.