A British hostage has been freed in Yemen after spending 18 months in captivity.
The man, understood to be Douglas Robert Semple, 64, was snatched in February 2014 by an armed group that threatened to kill him.
In a video released six months into his captivity, he appeared blindfolded and pleading for his life. "I think these kidnappers will kill me soon, please try to have me released,” he said.
The film was carried the name of the Alziadi tribe from Yemen’s northern Marib province, an area where Yemen’s al-Qaeda affiliate has maintained an active presence.
On Sunday, though, it was disclosed that Mr Semple had been freed unharmed after a military operation in the southern city of Aden by troops from the United Arab Emirates. The exact circumstances of his release were unclear, but Aden has been at the centre of fierce inter-factional fighting in recent months as a result of the collapse of the Yemeni government.
News that Mr Semple had been freed was confirmed by the Foreign Secretary, Philip Hammond, during a visit to Iran.
"I'm pleased to confirm that a British hostage held in Yemen has been extracted by UAE forces in a military intelligence operation," Mr Hammond said.
"The British national is safe and well, and is receiving support from British government officials. We are very grateful for the assistance of the UAE."
Mr Semple is believed to have worked for the petroleum services company Intracs Middle East Ltd until his abduction from the capital, Sana'a, where he lived and worked. He is understood to have children and grandchildren living in the UK.
Several Britons have been recently kidnapped in impoverished Yemen, where abductions are frequent as armed tribesmen and al-Qaeda-linked militants take hostages in an effort to swap them for prisoners or cash.
British-born American Luke Somers, 33, was shot dead by his al-Qaeda in the Arabian Peninsula (AQAP) captors in December as they fought US special forces attempting to extract him and South African teacher Pierre Korkie.
He was kidnapped in September 2013 in the capital Sanaa while working as a photojournalist.
In April 2010, the then British ambassador to Yemen, Tim Torlet, escaped unharmed when a suicide bomber wearing a school uniform detonated an explosives belt as he made his way to work in Sana'a. The following October his deputy, Fionna Gibb, escaped a rocket attack in the city.
The UAE is involved alongside Saudi Arabian forces in combating the Iran-supported Shia Houthi rebels and allied units of Yemen's fractured military as the country collapses into chaos.
News of Mr Semple's release came amid reports on Sunday that al-Qaeda had seized territory inside a western district of Aden.
Saudi Arabia began bombing military installations in Yemen in March after receiving a request for help from president Abd-Rabbu Mansour Hadi, who left the country by sea as the Houthis pushed towards the port city of Aden.
The air strikes had the support of several other countries in the region, but were condemned by Iran, which described the operation as an "invasion" and a "dangerous step" that will worsen the crisis.
Saudi Arabia and its allies believe the Houthis are tools for Iran to seize control of Yemen, though the Houthis deny they are backed by Tehran.