ADEN/SANAA,Yemen- Intense clashes erupted Thursday morning between Yemeni government forces and opposition militants, killing at least six people and injuring more than 26 others in Southern province of Taiz, witnesses and medics said.

"Four armed tribesmen and two civilians were killed and 26 others, including 10 civilians, were wounded in the clashes," a local medic told Xinhua.

Witnesses said the rival forces used artillery and heavy machine-guns in the clashes that took place before Thursday dawn in and around Rawda neighborhood in central Taiz city as the security forces blocked all roads leading to neighborhoods downtown.

Opposition leaders accused the government troops of attempting to storm Rawda neighborhood, a stronghold of the opposition armed tribesmen who pledged support for protesters against outgoing President Ali Abdullah Saleh.

On the other hand, a provincial security official told Xinhua on condition of anonymity that Taiz's general security head Abdullah Qairan was slightly injured on his neck by a gunshot by the opposition-led rebels on Thursday morning.

He added that two of Qairan's bodyguards were also wounded during the clashes.

The tribesmen set three armored vehicles of the Republican Guard on fire, the witnesses said, adding that dozens of residential houses were destroyed during the pitched street battles.

Heavy machine gunfire and explosions are still ringing out across the city, according to a local resident.

Taiz is a hotbed of the 10-month-long protest calling for ousting and prosecuting 33-year-ruler Saleh.

Saleh on November 23 signed a deal brokered by the Gulf Cooperation Council in the Saudi capital of Riyadh to transfer power to his deputy Abd-Rabbu Mansour Hadi in return for immunity from prosecution.

In line with the deal, Hadi nominated opposition coalition leader Mohamed Basindwa to form a new national interim government with equal seats from the opposition and the ruling party.

However, the rival forces through their media started to trade accusations of "military escalation" and blame the other one for seeking to breach the power-transfer deal.