Garowe - Gunman shot dead the head of Dubai government-owned P&O Ports' operations in Somalia's semi-autonomous region of Puntland on Monday, a local government official said, and Islamist militant group Al Shabaab claimed responsibility for the attack.

Yusuf Mohamed, governor of Puntland's Bari region told Reuters that two men disguised as fishermen had shot Paul Anthony Formosa as he was going to Bosaso port this morning.

Formosa was rushed to hospital where he died of his wounds.

One of the attackers was shot dead by security forces at the scene and the other detained, he said.

Paul Anthony Formosa who was the construction project manager for DP World, he was killed inside the port and the security forces also shot the killer on the spot", Mohamed Dahir, a local security official, told AFP.

Formosa, a Maltese national, was manager at Bossasso for P&O Ports, a subsidiary of the Dubai-based DP World.

Commenting on the incident P&O Ports, a Dubai Government Owned entity, confirmed the death of Formosa at Bossaso Port, Puntland today. Adding that other three employees have been injured in this morning’s incident, and all are currently receiving medical treatment.

"The circumstances of the incident are currently being investigated by P&O ports and the Puntland authorities and with the company’s full co-operation. The employee’s family have been notified and naturally our thoughts are with the family at this difficult time."

Adding "As this is an ongoing investigation, P&O ports will not be making any further comment until the full facts surrounding the incident are known."

Al Shabaab said it had carried out the attack and accused Formosa of being in Somalia illegally.

"We are behind the operation ... we had warned him but he turned deaf ear. He was illegally in Somalia," said spokesman for Al Shabaab's military operations, Abdiasis Abu Musab.

Huge blast heard in Somali capital Mogadishu

A huge blast was heard in the heart of the Somali capital Mogadishu on Monday and clouds of smoke could be seen rising, a Reuters witness said.

It was unclear what caused the explosion but Islamist militant group al Shabaab frequently carries out bombings in Mogadishu and other parts of Somalia against government military and other targets.

The group is trying to remove the Western-backed central government and establish its own rule based on its strict interpretation of sharia law.

Al Shabaab's militants also carry out attacks outside Somalia especially in Kenya to pressure the country to return its troops who form part of the peace keeping force AMISOM that helps defend the central government.

Its latest assault in Kenya, a suicide and gun attack at an office and hotel complex in the capital Nairobi last month killed 21 people.