ISLAMABAD, Dec. 25 (Xinhua) -- Two people were killed and five others injured as clashes between rival groups continued for the third day in Pakistan's northwestern tribal region on Tuesday, the Associated Press of Pakistan reported.

    The exchange of fires between rival groups in Kurram Agency in northwestern Pakistan's Federally Administered Tribal Areas spread to other villages of Sadda, Balachkhel, Khar Kallay, Sangina, Tangay, and Makhkizai, said the report.

    Up to 15 people have been killed while 50 others injured in a new wave of violence in the region since last Sunday.

    The clashes between the rival groups erupted on Sunday, claiming nine lives and injuring 20 others. They occupied key strategic positions in the nearby mountains and pounding each other with heavy weapons.

    People of the area have urged the government to take immediate measures to avert any more loss of life.