|Suspected al-Qaeda fighters have had more success against Yemeni security forces since the uprising [AFP]
At least four people have died and 12 others have been wounded after a Yemeni air force jet mistakenly bombed a bus transporting civilians in a southern city, security officials have said.
Wednesday's bombing on the passenger bus in Zinjibar, the provincial capital of Abyan, came as part of daily government attacks on suspected Islamic fighters, including suspected al-Qaeda members, who recently seized control over three towns in the province.
The fighters have taken advantage of the turmoil that has gripped the Gulf nation since a popular uprising that started in February against President Ali Abdullah Saleh's rule.
Shortly after the air strike on the bus, fighters in Zinjibar took over a football stadium on the city's outskirts and attacked government troops there, the officials added.
Authorties said at least 26 troops and 17 fighters were killed in the clashes in which government warplanes were called in and bombed the stadium.
Several government armoured vehicles were destroyed and officials said scores of fighters were wounded in the fighting.
Fighters kidnap citizens
Also in Zinjibar, officials said fighters seized 50 residents, accused them of passing information to the government, and detained them inside the governor's office.
|For more on Yemen, visit our Spotlight page
Mohammed al-Tumeisy, one of those seized and later released, said his captors had warned he would be executed if he made any contact with the government.
Officials said government planes also bombed the nearby town of Jaar on Wednesday, which was reportedly captured by fighters in early April.
All officials giving accounts of the fighting and casualties spoke on condition of anonymity because they were not allowed to speak to the media.
Air strikes on villages
Wednesday's fighting came a day after government warplanes and artillery attacked several villages of anti-government tribes north of Sanaa, the capital, killing at least three people, a senior tribal opposition leader said.
Ali Youssef of the Naham tribe said that Republican Guard forces, which are commanded by Saleh's son, bombarded the villages scattered in the Naham mountain area, about 30km north of Sanaa, on Monday and Tuesday.
Youssef also said 48 houses were destroyed and hundreds of people forced to flee their homes in the assault.
The Naham mountain area has seen a series of clashes between government forces and anti-Saleh tribes since the uprising.
Opposition tribesmen there have frequently prevented government troops stationed at bases in the area from deploying to the capital.