Militants linked to al-Qaida attacked an army post in an embattled southern province of Yemen but were driven back, leaving nine of their dead behind, officials said Thursday.
The security official said that one soldier was also killed in the Wednesday night firefight east of the town of Zinjibar in Abyan province.
Militants overran Zinjibar in May, shortly after a 10-month-old uprising against authoritarian President Ali Abdullah Saleh caused a breakdown of authority throughout the country.
The military patched up a temporary alliance with mutinous anti-Saleh units and fought their way back into the town in June, but have yet to establish full control and regularly clash with the Islamists.
Saleh late last month signed a U.S.-backed agreement in the Saudi capital of Riyadh, under which he is expected to step down by the end of this year.
Despite its potential to end the violence, many Yemenis reject the power transfer deal because it leaves much of the regime in place and offers the outgoing president immunity from prosecution.
Tens of thousands of Yemenis rallied in the capital Sanaa and several other cities calling for President Saleh to face trial for alleged corruption and killing of protesters.
Incoming Prime Minister Mohammed Basindwa announced on Wednesday that he had formed a national unity government composed both of Saleh allies and opponents to take over control of ministries.
But military units throughout the country remain divided in their loyalties. Some back Saleh or his family or other regime figures, and others are allied with his rivals in the powerful al-Ahmar clan or with other opposition forces.
The splits in Yemen's government and military provide a window of opportunity for al-Qaida, which has long had bases in the country, to continue to contest control of Abyan province and other territories.
A medic at a military hospital in the nearby city of Aden confirmed Wednesday's attack, and said that four wounded soldiers were under treatment. Both he and the security official spoke on condition of anonymity because they are not authorized to brief the media.
Meanwhile, two independent Yemeni websites said that the government had released the leader of a prominent south Yemeni secessionist movement who had been detained since February.
NewsYemen and Change said that Hassan Baoum, 71, of the Supreme Council for the Peaceful Southern Movement, walked free along with his son shortly after Basindwa's government was formed.
South Yemen was once a separate country plagued by deadly conflicts among groups vying for power. It merged with North Yemen under Saleh in 1990 but most of the people feel that they were unfairly treated by the northerners.