Sanaa: Battles between supporters of rebels in Northern Yemen and an Islamic group have killed 27 people over the past week, medical officials said.

The two sides are fighting for control of the lawless and remote Northeastern province of al-Jawf. Government forces were driven out of the area two months ago as part of the uprising against longtime President Ali Abdullah Saleh.

Security across Yemen has unraveled during the five-month uprising. The ruler of nearly 33 years has clung to power despite pressure to step down from his powerful Gulf Arab neighbors and the United States, which once considered him a necessary ally in fighting Yemen's active al-Qaida branch.

The United States and others worry that al-Qaida could exploit chaos in Yemen to step up its operations there.

A tribal official said the latest fighting erupted on Friday when supporters of the northern rebels refused to relinquish control of a military base they seized two months ago, setting off the fighting with the rival tribes. The official was speaking on condition of anonymity because he feared retribution.

A medical official said on Wednesday, fighting which began on Friday left 27 people killed, including 15 from supporters of the northern rebels, 10 from the rival group, and two civilians. The official, speaking on condition of anonymity as he was not authorized to speak to the press, said 22 injured.

In separate violence, a medical official in the southern city of Taiz said two were killed on Wednesday in clashes between the Republican guards and gunmen, who support the protesters. The city has come under heavy shelling and shooting by the guards, who are seeking to disperse the protesters. Residential areas were also hit, activist Bushra al-Muktari said.