Oct. 27 (Bloomberg) -- The commander of the United Nations' peacekeeping force in the Democratic Republic of the Congo has left the post as the mission prepares to defend territory from advancing rebels.

Lieutenant General Vicente Diaz de Villegas y Herrería, of Spain, ``indicated that for personal reasons he will not be able to continue with his assignment as planned,'' according to an e- mailed statement from UN Secretary-General Ban Ki-moon's office.

The UN has appointed Brigadier General Ishmeel Ben Quartey of Ghana to head the force while it looks for a replacement.

The peacekeepers are poised to defend Goma, the capital of eastern North Kivu province, as rebels from the National Congress for the Defense of the People, or CNDP, advance after two months of clashes between the CNDP and the national army.

UN peacekeepers shot dead two protesters today as they attacked UN bases in Goma, according to police chief Colonel Sengelwa Kyo. The demonstrators were protesting the peacekeeping force's failure to protect civilians and help the army, Kyo said in an interview from Goma.

Ban condemned the violence against the UN force and called today for a cease-fire and for renewed efforts to negotiate peace in the area, according to the UN. The UN chief said the peacekeeping force would take necessary measures to protect civilians and UN personnel. More than 100,000 people have been forced from their homes in the violence.

South Asian Soldiers

The United Nations Mission in Congo, or Monuc, comprises some 16,475 peacekeepers, with the largest contributions of soldiers from Pakistan, India, Uruguay and Bangladesh. Diaz took command last month. The Spanish general's posting was expected to last about a year.

The CNDP is a remnant from Congo's two civil wars between 1996 and 2003 in which as many as 4 million people died. Its leader, renegade general Laurent Nkunda, claims he is defending his Congolese Tutsi minority from the Democratic Forces for the Liberation of Rwanda, or FDLR, a mainly Rwandan Hutu militia active in the area.

The FDLR has formed a local alliance with Congo's army in areas they control in North and South Kivu, according to the UN.

To contact the reporter on this story: Robin Stringer in New York at rstringer@bloomberg.net; Franz Wild in Kinshasa via Johannesburg at pmrichardson@bloomberg.net.

Last Updated: October 27, 2008 15:39 EDT