The UK Foreign Office raised on Saturday the level of its travel advice to Yemen to "against all travel," warning Britons against travel to the state.

It said in light of the increasing violence in Yemen, "we advise against all travel to Yemen and recommend that all British nationals in the country without a pressing need to remain should leave by the commercial options currently available."

Britons in Yemen should also be aware of the threat of terrorism, kidnapping and tribal violence and remain in regular contact with the British Embassy there, it added.

The previous travel advice recommended "against all but essential travel" to Yemen, because of threat of terrorism, kidnapping and tribal violence.