Mogadishu -

Two UN workers, a Briton and a Frenchman, were shot dead on Monday as they disembarked from a plane at an airport in Galkayo, central Somalia, officials and witnesses said.

United Nations sources confirmed the two men were international consultants with the United Nations Office on Drugs and Crime (UNODC). Britain's Foreign Office confirmed one was a Briton, and sources identified the second victim as a Frenchman.

"Two white men have been shot inside the airport as they got off a plane," local security official Mohamed Mire said. An airport official said the attacker was dressed in a police uniform.

"One of them died inside the airport and the other one was rushed to hospital where he later died of the injuries. Both of them were white men," said witness Hassan Ahmed.

"We are aware of the death of a British national in Somalia on 7 April. We stand ready to provide consular assistance to the family at this difficult time," a Foreign Office spokesman said.

Galkayo is situated 575 kilometres north of the capital Mogadishu and lies on the border with the northern breakaway state of Puntland. UN security in Galkayo, which is outside of effective central government control, is normally extremely tight.

In Puntland UNODC efforts to combat piracy have included the construction of a new prison in the state capital Garowe. The prison takes in pirates who have been sentenced in other countries in the region, notably the Seychelles.

"The two were a Frenchman and a Briton and they were supposedly staying in Galkayo for two days before heading to Garowe," said Abdirisak Mohamed Dirir, general director of Puntland's anti-piracy department.

The two men had reportedly flown into Galkayo to meet with Somali officials on the issue of regulating the money transfer services that replace a formal banking system in Somalia.

Some accounts from the airport said the two had been shot close to the immigration office and the killing seemed to be a targeted assassination carried out by two assailants.

Other accounts said the two were shot by one policeman who appeared to be mentally disturbed. It was not clear whether anyone has been apprehended.

The UN Special Representative for Somalia, Nicholas Kay, condemned the killings.

"I condemn the brutal murders. Our UN colleagues were working in support of the Somali people's aspiration for a peaceful and stable future. There can be no justification for such a callous attack," Kay said, calling on the authorities to conduct a full investigation.

UN staff members have been regularly targeted in Somalia, where the fragile internationally-backed government backed by African Union troops is battling al-Qaeda-linked Shebab rebels.

In February at least six people were killed in a suicide car bomb attack targeting a United Nations convoy close to Mogadishu's heavily-fortified international airport, among them four local security escorts working for the UN.

In June last year the Shebab also carried out a raid against a UN compound in Mogadishu, killing 11 people. - Sapa-AFP