The US has withdrawn its last military contingent from the al-Annad air base near the southern Yemeni city of al-Houta, citing security concerns.

A military official was quoted by Agence-France Presse as saying that the US soldiers evacuated the airbase on 20 March, and moved to an ‘unknown destination.’

Yemen’s anti-terror unit personnel, who were trained by the US Forces and were based at Al-Anad, have also been pulled out, the source added.

In a statement, the US State Department Bureau of Public Affairs director Jeff Rathke confirmed that the US Government has temporarily relocated its remaining soldiers out of Yemen in the wake of deteriorating security situation in the country.

"The evacuation comes immediately after the AQAP fighters launched an offensive to take over the city of al-Houta."

"We will continue to engage the Yemeni people and the international community to strongly support Yemen’s political transition.

"We also continue to actively monitor terrorist threats emanating from Yemen and have capabilities postured in the area to address them."

Approximately 100 US troops, including Special Forces commandos, were believed to be stationed at the base, which was used by the US and European Military advisers to help Yemeni soldiers fight the Al Qaeda in the Arabian Peninsula (AQAP) militants through drone strikes and logistical support.

The evacuation comes immediately after the AQAP fighters launched an offensive to take over the city of al-Houta.

In addition, fighters belonging to an affiliate of the Islamic State group conducted a series of suicide bombings on two Shiite mosques in the capital city of Sana’a and in Saad’a on 20 March, killing at least 137 people and wounding scores of others.

The US, along with France and the UK, closed its embassy in Sana’a and evacuated staff last month citing deteriorating security situation in the country.

Meanwhile, Yemen’s Shiite rebels, Houthis, who currently control nine of the country’s 21 provinces, have called for a general mobilisation of their forces against those loyal to Yemen’s President Abd-Rabbu Mansour Hadi.