British helicopters have deployed to Mali in support of a French counter-terrorism operation amid warnings of being dragged into 'open-ended' conflict.

Three RAF Chinook helicopters supported by 90 military personnel have been sent to north-west Africa to assist French forces in their fight against Islamist insurgents.

The British helicopters, from RAF Odiham in Hampshire, will provide logistical and troop movement support. However, experts fear the deployment could mark the start of an open-ended commitment to a new military campaign.

The Telegraph understands the British forces have deployed to Gao, in the north of the country. The town has seen French troops targeted by insurgents in recent months and the helicopters will be used to move soldiers by air, rather than ground, where they are more vulnerable to attack.

Mark Lancaster, the Armed Forces Minister, said: “The UK and France have a unique security and defence relationship that has lasted for more than a century and this deployment demonstrates our shared commitment to tackling terrorism, instability and reducing threats to European security.”