An air raid on the presidential palace in Yemen's southern city of Aden and intense fighting at the airport Thursday raised fears for President Abedrabbo Mansour Hadi, who fled his residence.
Hadi was forced to evacuate the palace in the country's major southern city, presidency sources said, after it was attacked by a fighter jet.
The same sources claimed that the attack was repelled by anti-aircraft guns stationed near the palace, where Hadi was at the time, forcing the plane to retreat.
"President Hadi has been evacuated to a safe place but he has not left the country," the source told AFP as the plane made a second pass over the palace.
Security forces said the plane had opened fire but missed the palace, hitting a nearby hillside.
Hadi took refuge in Aden last month after fleeing house arrest under the Huthi militia that has taken control of the capital Sanaa.
The targeting of the palace came just hours after deadly clashes forced the closure of Aden's international airport.
At least six people were killed and 20 wounded after fierce fighting broke out between Hadi supporters and opponents, security sources said.
The clashes erupted between a special forces unit loyal to the Shiite Huthi militia, who since last year have seized large parts of central Yemen, and pro-Hadi paramilitary fighters, security sources said.
There was additional fighting across the city and further north, in Lahj province, which left another five dead.
The special forces fighting at the airport were led by renegade General Abdel Hafez al-Saqqaf and met heavy resistance from fighters with the Popular Committees, a local paramilitary group that backs Hadi.
Several hundred soldiers loyal to Hadi — supported by tanks and armoured vehicles — were also dispatched as reinforcements to the airport.
Three members of the special forces were killed along with two from the Popular Committees, sources said. Another special forces member was killed in separate fighting in central Aden.
Hadi loyalists regained control of the airport early Thursday after several hours of fighting, a military source told AFP.
Yemen, a key US ally in the fight against Al-Qaeda, has been gripped by unrest since ex-strongman Ali Abdullah Saleh stepped down in early 2012 after a year-long popular uprising against his rule.
Saleh — along with Iran — has been accused of backing the Huthis, who took control of Sanaa in September and earlier this year seized key government buildings in the capital.
Hadi resigned after the rebels seized his palace and named a "presidential council" to rule the country and assume the powers of the presidency.
He was placed under house arrest in Sanaa but resurfaced in Aden last month and retracted his resignation, despite being increasingly isolated in his southern Yemen power base.
Washington fears that the ongoing political instability will help al Qaeda in the Arabian Peninsula (AQAP), considered the jihadist network's most dangerous branch, to flourish.
During fighting Thursday shots were fired at the airport's control tower, witnesses said.
A military source told AFP that "Saqqaf's troops were forced to retreat to their camp (north of the airport) after being subjected to heavy shelling".
Saqqaf has defied a decree by Hadi sacking him and said he will only follow orders from the presidential council in Sanaa.
Flights were cancelled due to the clashes and had not resumed by midday Thursday.
One passenger who went to the airport said he had to turn back.
"I could not move. All access to the airport was blocked by armed men," he told AFP.
Roads leading to the airport were still closed by troops loyal to Hadi early on Thursday afternoon.
Other clashes were reported away from the airport including close to local government buildings in the centre of Aden and the local branch of the Central Bank, with reports that one special forces member was killed.
Meanwhile, in the province of Lahj, five members of the security forces were killed and another seven injured in an armed attack on their barracks in Houta, according to security sources.
It is not yet known who carried out the attack.
Also on Thursday, a local offshoot of al Qaeda, Ansar Al-Sharia, claimed it had carried out the assassination earlier this week of Abdel Karim al-Khiwani, a journalist who was a member of the Huthi militia.