Five Rwandan soldiers and two police officers, one from Ghana, the other from Uganda, were killed, said U.N. Secretary-General Ban Ki-moon's office, the Associated Press reported. At least seven of the wounded were in critical condition.
The incident took place Tuesday in Um Haqiba, which lies between a region controlled by Arab militias and an area dominated by rebels led by Minni Minnawi, said U.N. spokeswoman Sherene Zorba, reported Bloomberg News.
"In the last few weeks there has been tension between those Arab militia and the Minni Minnawi troops, and the patrol was there to carry out an investigation into the alleged killing of two Minni Minnawi soldiers," she said.
A spokesman for Sudan's Foreign Ministry, Ali Al-Sadiq, didn't answer his mobile phone when called for comment, according to Bloomberg News.
The joint U.N.-African Union force took over peacekeeping duties in Darfur earlier this year. About 9,000 soldiers and police have been deployed out of 26,000 authorized by the United Nations.
In October, 10 African Union peacekeepers were killed in an ambush at their northern Darfur base -- the deadliest attack on AU peacekeepers since they began their mission in late 2004.
An estimated 200,000 people have died and 2.5 million have been displaced since the conflict in Darfur began in early 2003 when black Africans from Darfur rebelled against the country's Arab Muslim leadership. The Sudanese government responded by sending in government forces to quell the rebellion.
The government also reportedly organized and supplied the Janjaweed militia to combat the rebels.
Sudanese officials deny any relationship with the Janjaweed militia, and dispute the commonly reported numbers of deaths, saying only 10,000 have died -- a number they say is normal for five years of war, CNN International reported.