UK-born US journalist Luke Somers and South African teacher Pierre Korkie have been killed by al-Qaeda militants in Yemen during a failed rescue bid.

Today's operation was carried out by joint US and Yemeni special forces in the southern Shabwa region.

US President Barack Obama condemned Mr Somers's death as a "barbaric murder".

They were being held by militants from al-Qaeda in the Arabian Peninsula, regarded by the US as one of the deadliest offshoots of al-Qaeda.

The group is based in eastern Yemen and has built up support amid the unrest which has beset the impoverished country since the overthrow of President Ali Abdullah Saleh in 2011.

President Obama said he authorised the raid to rescue Mr Somers and other hostages held in the same location.

He said information had "indicated that Luke's life was in imminent danger".

A number of militants were also killed in the operation.

"Terrorists who seek to harm our citizens will feel the long arm of American justice," Mr Obama said.

A US official told the New York Times that Mr Somers, 33, was apparently shot by his captors as the raid unfolded and was badly wounded when the US forces reached him.

By the time he was flown to a US naval ship in the region, he had died from his injuries, the official was quoted as saying.

Mr Somers was born in Britain and UK relatives have been mourning his death in Kent.

His step-mother, Penny Bearman, said that he was "very much loved" by people in Yemen.

"Luke was a peace-loving person who cared for the Yemeni people and the Yemeni struggle," she said, speaking from Deal. "It is a tragedy that his life should end in this way."

Mr Somers' sister, Lucy Somers, told the Associated Press earlier that she had been notified by the FBI of his death.

"We ask that all of Luke's family members be allowed to mourn in peace," Lucy Somers told AP.

Meanwhile a charity working with Mr Korkie said that they had expected his release on Sunday.

"Pierre Korkie was very sick - he had a hernia," Gift of the Givers' Yemen project director Anas Hamati told the BBC's Newshour.

Mediators had been working on an "arrangement to take him out", he said, adding: "His passport was ready, everything was ready.

"In that time the attack happened by US special forces in Yemen and that has destroyed everything."

Mr Korkie was abducted with his wife Yolande in May last year in Yemen's second city, Taiz.

She was freed on 10 January without ransom and returned to South Africa.

"The psychological and emotional devastation to Yolande and her family will be compounded by the knowledge that Pierre was to be released by al-Qaeda tomorrow," the charity said in a statement.

Mr Somers, who was kidnapped in Yemen in 2013, appeared in a video this week appealing for help.