Aden: An explosive device detonated next to the governor’s office in the southern Yemeni city of Aden on Thursday, a local official and witnesses said, killing four people and wounding 11, several of them critically.

The blast took place a month after fighters loyal to the country’s government in exile, backed by arms and hundreds of air strikes from Gulf Arab states, seized it from Iran-allied Al Houthi forces.

The governor was inside but unhurt, an official said.

Meanwhile, heavy Arab air strikes hit targets throughout northern Yemen on Thursday, local officials said, as the frontlines approach Al Houthi strongholds there.

The attacks hit five provinces controlled by the Al Houthis and the military airport in the capital Sana’a amid rapid ground advances by the Arab-backed Yemeni fighters.

The Saudi-led alliance began the air strikes in late March as the militia from Yemen’s north entered Aden, in a civil war that has killed over 4,300 people and left diplomats and air groups appealing for a ceasefire to spare civilians and alleviate a mounting humanitarian disaster.

Arab countries and Yemen’s Saudi-based government see the Al Houthis as a proxy of Iran bent on extending the Islamic Republic’s influence in the Arab world.

Al Houthis and Iran deny this, saying their armed spread is a revolution against officials and Arab countries aligned with Sunni militants like Al Qaida and subservient to the West.

Southern Yemeni militias and loyalist army units have scored major gains against the Al Houthis in the last month and may soon advance toward their stronghold around Sana’a.

But as a political accord remains elusive, suffering and hunger continue to spread especially after the coalition bombing of northern Yemen’s main entrepot in the Red Sea port of Hodeida this week.

Ertharin Cousin, the head of the UN’s World Food Programme, warned after a three-day visit to the country that the violence may push already widespread hunger out of control.

“Ten of the 22 governorates in Yemen in July were already at emergency levels. That’s one step away from famine. ”