Aden: Al Qaida militants on Wednesday blew up an army headquarters and set up checkpoints in the group’s southeastern stronghold of Al Mukalla, officials in Hadramout province said.

The militants had deployed in force across Al Mukalla after receiving information of a possible operation by a Saudi-led military coalition to help government loyalists retake the provincial capital, the officials said.

The coalition of Arab states has been carrying out air strikes against Iran-backed Al Houthi militants in Yemen since March, but has so far not intervened against Al Qaida.

Wednesday’s explosion flattened the three-storey army building - the command centre for a zone covering Hadramout and parts of neighbouring Shabwa province.

It came a day after Al Qaida dynamited a headquarters of the secret police in Mukalla, the officials said.

In Aden a 100-strong Saudi force arrived late on Tuesday and was deployed at the main southern city’s international airport, military sources said.

“This force’s mission is to help secure the city, where Al Qaida militants surfaced last weekend,” one of the sources said, referring to Aden.

Backed by arms and troops from Saudi Arabia and the United Arab Emirates, government loyalists recaptured Aden from Al Houthi militants and their allies in mid-July before retaking four other southern provinces.

But security has remained fragile in the port city, where Al Qaida suspects were accused of blowing up a building used by the secret police.

They also set up checkpoints in one district and seized five buildings including an intelligence services facility, a presidential residence and a military hospital, security officials said.

On Tuesday, the International Committee of the Red Cross said it had suspended its operations in Aden after unidentified gunmen stormed its office there.