The MV Zirku was heading from Sudan to Singapore [EU NAVFOR]

Pirates have hijacked a Kuwaiti oil tanker with 29 sailors aboard southeast of Oman, according to the European Union's anti-piracy task force.

The MV Zirku was heading to Singapore from Sudan and was attacked by pirates in two skiffs armed with rocket-propelled grenades and guns, EU Navfor said.

The crew include 17 Pakistanis as well as Egyptians, Jordanians, Ukrainians, an Indian, a Filipino, an Iraqi and a Croatian.

But Kuwait's state oil company, the Kuwait Petroleum Corporation, denied the ship had been hijacked, calling EU Navfor's statement "totally incorrect", according to Kuwait's state news agency.

Pirates in the Gulf of Aden, mostly operating from Somalia, are a growing problem for shipping in the region. Piracy is estimated to cost the global economy an estimated $7 billion to $12 billion a year.

More than 20 countries are currently engaged in counter-piracy patrols in the Indian Ocean but concerns have emerged that a lack of co-ordination is hampering efforts to bring the problem under control.

On Monday Somalia and India announced plans to agree a common strategy to tackle piracy in the region.