7 U.N. Peacekeepers Killed in Sudan Attack, Official Says CAIRO - Gunmen ambushed a United Nations peacekeeping team Saturday in Sudan's western region of Darfur, killing seven Tanzanians and wounding another 17 people in the deadliest ever single attack on the international force in the country, U.N. officials said. The assault by a large group of gunmen included sustained heavy fire from machine guns and possibly rocket-propelled grenades, targeting the force some 25 kilometers (15 miles) west of the town of Khor Abeche, U.N. forces spokesman Chris Cycmanick said. Reinforcements later arrived to rescue the wounded, who included two female police advisers, the force said in a statement. A statement late Saturday on behalf of U.N. Secretary-General Ban Ki-moon identified the dead as all being from Tanzania. About 40 countries have contributed military personnel or police to the peacekeeping force. The statement said Ban condemned the "heinous attack" and offered condolences to the families of the dead. The statement said it was the third attack on U.N. forces in the region in the last three weeks. Ban "expects that the government of Sudan will take swift action to bring the perpetrators to justice," the statement read. Officials with the Sudanese government could not be immediately reached for comment. Peacekeepers have been targeted by assailants in the past in the region since the international force began its work there in 2008. In the last fatal attack, gunmen shot dead a Nigerian peacekeeper in April in East Darfur State. Before Saturday's attack, 150 people associated with the U.N. mission had been killed while on duty in the region, according to the force's website. The joint African Union-U.N. peacekeeping force, dubbed UNAMID, was established to protect civilians in Darfur, but also contributes to security for those providing humanitarian aid, verifying agreements, political reconciliation efforts and promoting human rights. It has about 16,500 troops and military observers and over 5,000 international police. No group immediately claimed responsibility for the assault Saturday. Tribal clashes remain common in the region and some former government militias have begun taking up arms again as fighting continues over land and resources. A February report by a U.N. panel of experts said that some armed opposition groups angry about the presence of peacekeepers have called the force "a legitimate target." "On occasion, this discontent has also manifested itself in incidents of direct attacks on UNAMID staff and premises, although some of these incidents - especially those of carjacking and kidnapping of UNAMID peacekeepers - appear to have an overtly criminal intent of financial gain for the perpetrators," the report said. Darfur has been gripped by bloodshed since 2003 when rebels took up arms against the government in Khartoum. More than 300,000 people have been killed in the conflict. The International Criminal Court indicted Sudanese President Omar al-Bashir in 2009 on genocide and war crimes charges over the fighting in Darfur. The country split into Sudan and South Sudan in 2011. Unrest continues in the region. About 300,000 people have fled fighting throughout Darfur in the first five months of this year, the U.N. has said. "The mission condemns in the strongest possible terms those responsible for this heinous attack on our peacekeepers," said Mohamed Ibn Chambas, a joint special representative of the force. The perpetrators should be on notice that they will be pursued for this crime and gross violation of international humanitarian law. More than 100 U.N. peacekeepers were killed last year alone on duty in the Darfur and Abyei regions of Sudan, Congo, Ivory Coast and other countries. Eight more civilian contractors, such as pilots, also died on deployment with peacekeeping missions in 2012. Associated Press writers Michelle Faul in Lagos, Nigeria, and Edie Lederer in New York contributed to this report. Jon Gambrell can be reached at www.twitter.com/jongambrellAP .