Three Chinese citizens have been shot dead in their apartment in the Afghan capital while one of two others who were missing has been found alive, officials said Saturday.

Police said the murder victims, two women and a man, were shot late on Thursday along with their Afghan guard but their deaths were only reported by a neighbour on Friday.

"Initial investigations show they were perhaps prostitutes killed by a gun with a silencer," Mohammad Zahir, head of the criminal investigation department told AFP.

"Two Chinese men are missing, we have launched an investigation to find them."

The Chinese embassy in Kabul later said one of the two missing men had been found alive and transferred to a safe place, according to state news agency Xinhua.

It said the five were all self-employed business people and the two women were killed accidentally when they stopped at the apartment while criminals were inside, the agency reported.

Earlier the embassy confirmed the incident and asked the government to ensure the safety and security of its citizens and institutions in Afghanistan.

No one has claimed responsibility for the attack. In the past, both the Taliban and criminal groups have been involved in the kidnapping and killing of foreign nationals in Afghanistan.

There are hundreds of Chinese working on different projects in Afghanistan.

China, which shares a 76-kilometre (47-mile) border with Afghanistan's far northeast, has secured major oil and copper mining concessions in Afghanistan, which is believed to have more than $1 trillion worth of minerals.