Yemeni security forces clashed with Islamist fighters near a southern town overrun by militants, leaving seven Islamists and a soldier dead, officials said, as tens of thousands staged rallies across Yemen calling for the president to step down.
Security across the impoverished nation in the southern corner of the Arabian Peninsula, home to an active al-Qaida branch, has largely collapsed since the uprising seeking to oust President Ali Abdullah Saleh broke out in February.
Islamist fighters seized Zinjibar and another town in the southern Abyan province earlier this year, and Yemeni troops have sought to push them out.
Wednesday's clashes broke out when Islamist fighters attacked an army base west of Zinjibar, but were repelled.
Yemen's Defense Ministry said in a statement that seven Islamists were killed and two arrested during the attack. Medics said one soldier was killed and three injured in the clashes.
More than 54,000 Abyan residents have fled the fighting, said Ahmed al-Kohlani, a state minister. He said many relocated to the port city of Aden, where schools were turned into shelters.
To the west, near the city of Taiz, medical officials said two soldiers were killed in clashes with armed tribesmen. Taiz is a hotbed of opposition protests.
The fighting raged in different areas outside the city throughout the day Wednesday, with government forces firing heavy artillery at positions held by tribal fighters. Military officials said the soldiers were killed when tribesmen attacked a checkpoint. Eyewitnesses elsewhere said tribal fighters set fire to three military vehicles.
Later Wednesday, mortars hit a residential area in Taiz, killing a civilian and injuring eight, a security official said.
Also Wednesday, port officials in the port city of Aden said pirates seized an oil tanker off Yemen's coast before Yemeni and international forces intervened and freed the ship. The ship had left the Saudi port of Jiddah and was heading for Sri Lanka, flying a Panamanian flag, the officials said.
All officials spoke on condition of anonymity because they were not authorized to brief the media.
There have been near-daily protests demanding that Saleh step down. The president has been in Saudi Arabia since June 5, undergoing treatment for injuries sustained in an attack on his presidential compound.
On Wednesday, an opposition statement accused him of trying to create chaos in Taiz and in the province of Abyan. The statement alleged that Saleh pulled his security forces from several cities in Abyan, enabling Islamic extremists and al-Qaida-linked groups to exploit the turmoil and take control.