A Chinese national was killed and three others wounded in an attack in Laos, state media reported Wednesday, the second time this year workers from China have been targeted in the resource-rich nation.

The assault took place late Tuesday on property belonging to a Chinese-backed company in Laos' Luang Prabang province, Xinhua news agency said, without naming the business.

The report did not say who was behind the violence or why the workers may have been targeted.

But it said a pick-up truck and bus passing through the same district were also attacked later that night, leaving at least five Laos nationals injured.

Laos police were dispatched to "wipe out the militants," the report said.

Luang Prabang is a tourist haven, and the main city is a UNESCO site renowned for its colonial-era architecture and natural beauty.

The district where the attack took place is north of Xaisomboun, a province that has seen a spate of deadly bomb and gun attacks in recent months.

In January, two Chinese nationals were reportedly killed, including an employee of a Chinese mining company, and one injured in a suspected bomb attack in a mountainous region, prompting a travel warning from the US Embassy in Vientiane.

In the past, the area has hosted a shadowy insurgency by ethnic Hmong against Laos' Communist rulers.

The rebels are believed to be the remnants of anti-Communist militias recruited by the United States during its secret operations in Laos amid the Vietnam War.

Neither Laos nor China's Communist leaders touched on a suspected motive behind the assaults against Chinese nationals.

However Beijing's growing footprint in the poor nation has stirred unease in among locals in recent years.

China has invested heavily in Laos and funnelled its water, forestry and mineral extracts back to the mainland.

Laos will host president Barack Obama later this year as the culmination of its chairmanship of the ASEAN regional bloc.