By Michelle Nichols

UNITED NATIONS (Reuters) - In a special report to the U.N. Security Council on Wednesday, Secretary-General Ban Ki-moon toned down criticism of Rwanda over accusations that it supports rebels in the Democratic Republic of Congo, but still warned against external support for the revolt.

A draft of Ban's report seen by Reuters on Monday had applauded states who suspended aid to Rwanda after U.N. experts, who monitor compliance with sanctions and an arms embargo on Congo, accused Rwanda of supporting M23 rebels in eastern Congo.

The draft report read: "Actions taken by some bilateral donors to suspend aid and funds to those countries reportedly supporting in particular the M23 send a strong message that such practices must cease immediately.

But in the final report, sent to the 15-member Security Council on Wednesday, that statement was removed. Ban did not name any countries in his report, but that paragraph was a clear reference to Rwanda.

Rwanda has strongly denied any involvement in the M23 rebellion in resource-rich eastern Congo.

Ban's final report did provide a less specific warning that "ongoing support to armed groups by neighboring countries continues to be a source of serious instability, and should have tangible consequences for perpetrators."

M23 began taking parts of eastern Congo early last year, accusing the government of failing to honor a 2009 peace deal. That deal ended a previous rebellion and led to the rebels' integration into the army, but they have since deserted.

The U.N. Security Council's Group of Experts, which monitors compliance with sanctions and an arms embargo on Congo, said in a report last year that Rwanda's defense minister was commanding the M23 revolt in Congo and that Rwanda was arming the rebels and supporting them with troops.

The United States, Sweden, the Netherlands, Britain and the European Union reacted to the experts' accusations by suspending some aid to Rwanda, which relies on donors for about 40 percent of its budget.

The U.N. Security Council had requested the report from Ban on the Democratic Republic of Congo. As expected, Ban recommended that an intervention force of several thousand troops be created within the existing U.N. peacekeeping force in Congo to fight armed groups, including M23.

Ban is due to brief the council on his proposals next week.

The Security Council will now need to pass a new resolution authorizing the force and diplomats have said it will likely be supported. African leaders signed a U.N.-mediated deal on Sunday aimed at ending two decades of conflict in Congo's east and approving the creation of the intervention brigade.

Ban recommended that the intervention brigade initially be deployed for one year. It is a peace enforcement mission, which allows the use of lethal force in serious combat situations. Diplomats say South Africa, Tanzania and Mozambique are the most likely candidates to supply the troops for the new force.

In practical terms, U.N. diplomats say, troops in the brigade will have more freedom to open fire without having to wait until they are attacked first, a limitation that is standard for U.N. peacekeepers deployed around the world.

(Reporting by Michelle Nichols; editing by Christopher Wilson)