Washington, Oct 16 (IANS): Two American citizens held by Houthi rebels in Yemen have been released and flown to neighbouring Oman, the US State Department announced.

State Department spokesperson Mark Toner on Saturday said that consular officers from the US Embassy in Muscat, stood ready to provide all possible assistance, Xinhua news agency reported.

"We are deeply grateful to His Majesty Sultan Qaboos bin Said Al Said and the Government of Oman for their assistance in facilitating and supporting the release of our citizens," Toner said, adding "We recognise the humanitarian gesture by the Houthis in releasing these US citizens."

The US calls for the "immediate and unconditional" release of any other American citizens who may still be held, the spokesman added.

A Houthi official said on Saturday that his group released the two US nationals detained in Yemen's capital Sanaa on charges of espionage in a deal meditated by Oman in return for allowing a Houthi delegation to return home.

"We handed over the Americans to Omani authorities on Saturday ... they will be airlifted through the same Omani plane that carried the national (Houthi delegation) and arrived in Sanaa at noon," the official told Xinhua news agency.

He said that one of the Americans is an English teacher who was arrested on September 21.