Gunmen stormed an office of Iraq's Human Rights Ministry in the capital of Baghdad on Thursday and seized a number of officials, a police source said. The attack occurred before noon when eight gunmen broke into the office in al-Qanat area after a clash with the guards and took unknown number of officials as hostages, the source told Xinhua on condition of anonymity. There was no immediate reports about casualties, the source said. Iraqi security forces surrounded the area, which included several government buildings, and stared negotiation with the attackers, the source added. Iraq is witnessing its worst violence in recent years. According to the UN Assistance Mission for Iraq, a total of 8,868 Iraqis, including 7,818 civilians and civilian police personnel, were killed in 2013, which is the highest annual death toll for years.