Seven members of a Sihanoukville family – including five children – were brutally assaulted as they slept early yesterday morning by an unknown assailant wielding an axe, police have said.

Three of the victims, a 1-year-old child, the children’s 65-year-old grandmother and their 32-year-old mother, Um Phanna, were whisked to hospital in Phnom Penh in critical condition.

The other four children remain in Chamkachek Hospital in Sihanoukville and are said to be stable.

Shocking images taken by police of the crime scene and published in local media show the children sprawled across their shared bed spattered with blood.

The children’s father was on a fishing trip and re-turned home yesterday afternoon to the traumatic news his entire family had been hospitalised.

The family members, who are from Village 1 in Sihanoukville’s Commune 1, were sharing a bed when the attacker entered their house and began hacking at the family.

“They are all now staying at Chamkachek Hospital and the seriously injured victims were sent to Phnom Penh. Another two of the children have swelling around their heads,” said Phan Narith, Sihanoukville deputy police chief.

He added that the as-yet-unidentified attacker fled the scene after the assault some time between 12am and 1am yesterday morning.

Police have yet to definitively determine a motive for the attack, but Narith yesterday suggested it was likely caused by an outstanding grievance.

“The family just recently settled in the area . . . We suspect this case was a premeditated act, but we cannot discuss the details yet,” he added. “Our authorities are actively and attentively working on this case to bring the suspect to justice.”

James McCabe, operations manager with the Child Protection Unit, which is helping coordinate the investigation, said a joint task force had been established to “investigate the home invasion and attempted murder of five children, their mother and grandmother”.

“At this stage, we’re still looking for a motive,” he said. “The investigation is ongoing and all available resources are being mobilised.”

Preah Sihanouk provincial police chief Chuon Narin said the authorities were continuing to search for the suspect or suspects yesterday evening.

“We cannot reveal the authorities’ methods of investigation in this case; we will explain at a later stage. For now, we are gathering information,” he said.