"Any ground attack on Yemen will receive a rigidly harsh response," al-Bakhiti said on Sunday.

"We have not responded to the Saudi aggressions in the past five days because we wanted to allow the Arab countries to reconsider their action and stop their attacks," he said, and added "but from now on everything will be different".

Al-Bakhiti described the Saudi-led alliance against Yemen as a moral crisis, and said, "Whatever the Arab conference decided about Yemen will end in serious crisis."

On Saturday, a senior member of the popular Ansarullah movement warned of immediate attacks on Saudi territories if the latter refrains from putting an immediate halt to its aggression against Yemen.

"As the Ansarullah movement has promised collapse of some Arab regimes supporting the terrorists, if Saudi Arabia continues its aggressions against the oppressed Yemeni people the Ansarullah fighters will pave the way for the Saudi regime's destruction by operations inside Saudi Arabia in the coming hours," member of Ansarullah Executive Committee Abdel Mon'em Al-Qurashi told FNA.

Today Ansarullah fighters on Sunday regained control over Aden International Airport after heavy clashes with the forces loyal to fugitive Yemeni President Abed Rabbo Mansour Hadi, media reports said.

The forces loyal to Mansour Hadi had seized control of the airport only three days ago, and German news agencies reported that Ansarullah could defeat them and took it back today.

The Ansarullah fighters also made major advances in the surrounding areas of the airport.

Medical sources, meantime, confirmed that a sum of 113 forces loyal to Mansour Hadi were killed in Sunday clashes in Aden.

Saudi Arabia has been striking Yemen for four days now, killing, at least, 173 civilians and injuring hundreds more.