BANJUL, (Reuters) – Gambian police seized 2.34 tonnes  of cocaine bound for Europe and arrested a dozen suspected  traffickers after a joint investigation with British detectives,  a security source said yesterday.

West Africa has become a major transit point for Latin  American narcotics as smugglers take advantage of generally weak  surveillance in the vast region.

The cocaine, which has an estimated street value of around  $1 billion, was found last Friday hidden in a warehouse outside  Gambia’s capital Banjul, the source told Reuters.

He said a cache of guns and money was also seized.

Gambian authorities began making arrests related to the case  in mid-May and subsequently invited Britain’s Serious Organised  Crime Agency to help, the source said.

Those arrested included Nigerians, Ghanaians, Venezuelans,  and Dutch, the source said without giving further details. Analysts have said increased drugs trafficking through West  African states like Guinea Bissau, Guinea and Liberia could  further destabilise a region notorious for coups and rebellions.