The British Foreign Office has summoned the Yemeni ambassador in London for the second time in two days.

Reports say the meeting was called because of continuing dissatisfaction over the conflicting accounts of the shoot-out in Yemen last Tuesday that led to the deaths of three British tourists and an Australian held hostage by gunmen.

Teams of British and American detectives have gone to Yemen to help with inquiries.

Yemeni security forces have maintained they had no choice but to open fire on the kidnappers -- who've identified themselves as members of Islamic Jihad.

Ten of the survivors from the operation are due to arrive have arrived - ETA 1915 in London shortly.