* Rwanda says U.N. peacekeepers in talks with Hutu rebels
* Intervention force intends to neutralize rebels
U.N. Secretary-General Ban Ki-moon has asked Rwanda's government for evidence to support its allegation that U.N. peacekeepers in Congo discussed collaboration with Hutu rebels linked to the 1994 Rwandan genocide, a U.N. spokesman said on Friday.
In a letter to U.S. Ambassador Rosemary DiCarlo released early this week, Rwandan U.N. Ambassador Eugene-Richard Gasana said U.N. intervention brigade commanders in the Democratic Republic of Congo have met with rebels from the Democratic Forces for the Liberation of Rwanda (FDLR).
The FDLR is made up of the remnants of Hutu killers who carried out the 1994 genocide of Tutsis and moderate Hutus in Rwanda.
The letter, which was sent to DiCarlo in her role as this month's president of the U.N. Security Council, said Rwandan Foreign Minister Louise Mushikiwabo also wrote to Ban about the same matter.
In a letter to Mushikiwabo, Ban "notes with deep concern the allegations that meetings have taken place between senior commanders of the MONUSCO and the Intervention Brigade and the (FDLR)," Ban's spokesman Martin Nesirky told reporters.
The United Nations Organization Stabilization Mission in the Democratic Republic of Congo (MONUSCO) is a 17,000-strong U.N. peacekeeping force that has been in the mineral-rich eastern DRC for more than a decade.
It is the largest U.N. peacekeeping force in the world.
The complex conflict has dragged on, with millions of people dying from the violence, famine and disease since the 1990s.
That has led the United Nations to create a new "intervention brigade" - part of the MONUSCO force but assigned the additional task of taking active steps to neutralize armed groups, above all M23 rebels in eastern Congo.
M23 is a Tutsi-dominated movement made up of former Congolese soldiers that has demanded political concessions from President Joseph Kabila's government.
Ban said there was nothing so far to back up the allegations of Rwanda, which also accused MONUSCO and Congo's army of deliberately bombing Rwandan territory on Monday.
"Following initial inquiries within MONUSCO, (Ban) has no reason to believe that senior commanders of the Force Intervention Brigade would meet with the FDLR to discuss matters related to their 'tactical and strategic collaboration'," Ban said in his letter, according to Nesirky.
Nesirky added that it was "important to ensure that these allegations are properly addressed ... (and) has thus requested that the Rwandan Government share as soon as possible any concrete evidence it may have to substantiate these claims."
A Rwandan diplomat said Ban's letter was received on Wednesday and that Kigali has not yet responded.
Ban and MONUSCO have also denied U.N. involvement in any bombing of Rwandan territory.
In its complaints to the United Nations, Rwanda also supported an allegation in the latest report by the U.N. Group of Experts that units of the Congolese army have been cooperating with the FDLR.
Heavy fighting erupted between the army and the M23 rebels on Sunday some 12 km (7.5 miles) northeast of Goma, ending several weeks of relative calm and reviving memories of an attack in November when the Tutsi-led insurgents briefly seized the city of 1 million people.
Hundreds of people protested in Goma on Thursday against Kabila, accusing him of incompetence in efforts to neutralize rebels who have long plagued the region.
Nesirky said MONUSCO reported on Friday that "the situation remains calm but tense around the city of Goma, in North Kivu province. It (MONUSCO) says that fighting between the Congolese armed forces and the M23 armed group has stopped."
The Congolese government also rejected Rwanda's allegations and again accused it of backing M23 rebels. The U.N. Group of Experts said in their latest report that Rwanda had decreased but not ended support for M23, a charge Kigali dismissed.