Gunmen launched simultaneous attacks on Wednesday on the intelligence and security services headquarters in the south Yemen town of Zinjibar, killing one policeman and wounding eight, medical officials said.
One gunman was killed and one wounded in the clashes, the medics said, while a security official said the attacks bore the hallmarks of Al-Qaeda.
Witnesses said gunmen on motorbikes armed with rocket-propelled grenades, assault rifles and grenades began attacking the two headquarters at around 8:00 am (0500) GMT.
After a fierce firefight, the attackers fled toward Jaar, north of Zinjibar, the witnesses added.
The security official said that the attack on intelligence headquarters was carried out by five motorcyclists, but did not say how many attacked the security services headquarters.
"It seems Al-Qaeda was behind the attacks," the official told the news agency.
Security forces cordoned off the sites of the attacks and closed the main streets of the town, which is in Abayan province, for over an hour, the witnesses said.
Zinjibar is located about 25 kilometres (15 miles) northeast of Aden, where 11 people, including seven security forces members, were killed in a June 19 attack on the intelligence headquarters. That attack has been claimed by Al-Qaeda.
The Yemeni defence ministry said on Sunday that eight Al-Qaeda members had been captured in the south since the June attack.
Yemen, the ancestral homeland of Osama bin Laden, has witnessed numerous attacks claimed by Al-Qaeda on foreign missions, tourist sites and oil installations.
Sanaa has intensified operations against Yemen-based Al-Qaeda in the Arabian Peninsula (AQAP) in the wake of the attempted December 24 bombing of a US airliner by a Nigerian believed to have been trained and supplied the group.
AQAP has suffered setbacks amid US pressure on the government to crack down. But its presence threatens to turn Yemen into a base for training and plotting attacks, a senior US counter-terrorism official said in September.
In addition to the threat from Al-Qaeda, Yemen, the Arab world's poorest country, must also contend with the aftermath of a long-running Zaidi Shiite rebellion in the north and a separatist movement in the south.
South Yemen, where many residents complain of discrimination by the Sanaa government in the allocation of resources, is the site of frequent protests and periodic unrest.
The impoverished country's south was independent from 1967 until 1990 when it united with the north. The south seceded in 1994, sparking a short-lived conflict that ended when the south was overrun by northern troops.