Nigeria's military chief said Thursday the Islamist Boko Haram sect, blamed for attacks that have claimed hundreds of lives, has ties to Al-Qaeda, the first time a top security official has publicly drawn such links.

"We have been able to link the activities of the Boko Haram sect to the support and training the sect received from AQIM (Al-Qaeda in the Islamic Maghreb)," Air Chief Marshal Oluseyi Petinrin said.

He did not elaborate.

It was the first such public comment by a top security official in Nigeria linking the group to Al-Qaeda.

Petinrin's remarks were contained in speech read out at a meeting of security chiefs from the West African bloc ECOWAS by Nigeria's navy chief Vice Admiral Sa'ad Ibrahim.

A summit of leaders from 15 ECOWAS member states last week ordered an "urgent" meeting of security chiefs to draw up concrete plans to curb emerging security threats in the Sahel region and the Gulf of Guinea.

"Piracy and sea robbery which has continued to thrive in the maritime domains of some member states within the Gulf of Guinea has remained a matter of serious concern with its attendant implications on socio-economic and political development of the sub-region," he said.

The International Maritime Bureau (IMB), which is funded by shipowners, warned in September that the seas off Benin, Nigeria's neighbour, were emerging as a new piracy "hotspot" due to the weak enforcement capabilities of governments in the region.

The Economic Community of West African States (ECOWAS) comprises 15 nations, some of which have been victims of Al-Qaeda and maritime piracy attacks.

Earlier Thursday, gunmen on motorcycles shot dead four policemen near the home of Nigeria's police chief Muhammad Abubakar in the main northern city of Kano, in an attack that was suspected to have been the work of Boko Haram.

Security chiefs from Benin, Ivory Coast, Mali, Niger and Nigeria attended the day-long meeting of security chiefs from the West African bloc ECOWAS.

"We all have had our individual and collective challenges to security and defence in the ECOWAS sub-region," he stated.

"The instability in Libya and the activities of Al-Qaeda in the Islamic Maghreb (AQIM) has no doubt had a spill-over effect into our sub-region," said Petinrin in the speech.

Boko Haram launched an uprising in 2009 put down by a brutal military assault that left some 800 people dead. After lying dormant for about a year, it has re-emerged with a series of shootings and bomb attacks that rights groups say have killed more than 935 people since mid-2009.

The sect's deadliest ever assault left 185 people dead last month in Nigeria's second largest city of Kano.

The group claimed responsibility for the Christmas day bomb attack on a Roman Catholic Church outside Abuja which claimed at least 44 lives two months ago.

A previous bomb attack last August on the UN headquarters building also claimed by the sect killed 25 people.