TRIPOLI: Three Sudanese migrants were killed in a shooting in Libya after the country's coast guard intercepted them at sea and returned them to shore, the UN refugee agency said Tuesday.

The International Organization for Migration said separately that "local authorities started shooting when the migrants attempted to escape from the disembarkation point".

The UNHCR said it "deplores the tragic loss of three lives and calls for an urgent investigation" into the shootings at Al-Khums, a port city about 100 kilometres (60 miles) east of Tripoli late Monday.

"The shooting occurred after more than 70 people were disembarked from a vessel," the UNHCR said, adding that two migrants died at the scene and a third en route to hospital, while two more were wounded.