Yemen's president has been forced to flee his presidential palace after two fighter planes targeted his residence in Aden, a government official has said.

President Abd-Rabbu Mansour Hadi was evacuated on Thursday after the planes opened fire, hitting his residence in the southern city.

"President Hadi has been evacuated to a safe place but he has not left the country," Hadi's aide told the AFP news agency as a plane made a second pass over the palace.

The aircraft dropped a bomb or fired a missile at the compound in al-Maasheeq district of the southern port city, where Hadi is based, the official said, in a sharp escalation of Yemen's months-long armed turmoil.

Residents said anti-aircraft guns opened fire at the planes, and smoke was seen rising from the area, but it was not immediately clear if Hadi was in the compound.

A Yemeni security source said the situation at the presidential palace "was under control and there was nothing to be worried about".

Airport clashes

The attack on Hadi's compound came after forces loyal to Yemen's former president forced the closure of Aden's international airport after clashes left at least thirteen people dead and 13 wounded, security sources said.

A special forces unit, led by renegade General Abdel Hafez al-Saqqaf, stormed the airport grounds on Thursday before being repelled by fighters linked to the current president, Abd-Rabbu Mansour Hadi.

A military source told the AFP news agency that "Saqqaf's troops were forced to retreat to their camp [north of the airport] after being subjected to heavy shelling."

During the hours-long fighting, more than a 100 passengers who had boarded a Yemenia aircraft flight to Cairo, were ordered off a plane as machinegun fire rang out and explosions shook the terminal building.

At least two shells hit the airport's grounds, security and aviation officials at the scene said, with at least thirteen people killed and 13 wounded. Another 10 others were captured.

Sporadic clashes also erupted throughout Aden. Sounds of explosions periodically shook the city, and streets were largely deserted as residents hid in homes.

Meanwhile, a fighter jet attempting to target Hadi's palace in Aden hit a nearby hill instead, leading to smoke billowing in to the sky.

Speaking to Al Jazeera from the Yemeni capital Sanaa, Hakim Al Masmari, editor in chief of the Yemen Post, said the forces who lanched the assault were still in Aden and were expected to continue attacks against Hadi.

Tensions have been building in Aden for days. Hadi loyalists dominate the city, but two army units are loyal to Saqqaf, a pro-Saleh commander, who leads a force of 3,000 special forces police.

Hadi unsuccessfully tried to remove al-Saqqaf from his post earlier this month, prompting some clashes.

Hadi insists he remains the country's legitimate leader and enjoys much support in Aden, where he has been based since fleeing house arrest in Sanaa last month.