“September 26”, a defence minister publication, said Nayef Yahya al-Harbi surrendered after security forces had been searching for him.

Yemen said last week it had arrested a man described as al Qaeda’s top financer in Yemen and Saudi Arabia. Three foreign hostages were killed this week after being seized in the mountainous Saada province in an attack that an analyst said bore the hallmarks of al Qaeda.

Yemen has pledged to hunt down those behind the rare killing of three hostages identified by officials as two German nurses and a Korean teacher, and offered a reward of $275,000 for information leading to the capture of the kidnappers.

Yemeni authorities have blamed the Houthi tribal group, who belong to a Shia Muslim sect, for kidnapping the nine foreigners, a charge the Houthis have denied.

Yemen, the Arab world’s poorest country, is struggling with a Houthi-led revolt in the north, a secessionist movement in the south and al Qaeda militancy.

The unrest has raised concerns in the United States and neighbouring Saudi Arabia that Yemen could slip into chaos and provide a base for al Qaeda or pirates operating in the Indian Ocean.