In its second non-binding statement issued since the violence began over a month ago, the 15-nation council ordered Kenya to "immediately end violence, including ethnically motivated attacks, dismantle armed gangs, improve the humanitarian situation and restore human rights."

The clashes in Kenya were sparked by a dispute over the December 27 re-election of President Mwai Kibaki which opposition leader Raila Odinga says was rigged.

Most of the more than 1,000 deaths have come from ethnic killings, adding to fatalities from police clashes with protesters.

Last week a U.S. official suggested the violence in Kenya constituted "ethnic cleansing", but U.N. officials have said there was no point in applying labels to the situation.

The council statement, much more strongly worded than last week's, also expressed "strong concern at the continuing dire humanitarian situation in Kenya and (called) for the protection of refugees and internally displaced persons."

It also reiterated the council's support for mediation efforts led by former U.N. chief Kofi Annan.

An earlier version of the statement drafted by France and Britain said the council "regrets the abuses in the presidential election noted by international and domestic observers." But this was removed due to Russian objections, diplomats said.

The statement did not say what further steps the council might take if the violence continues.

Separately, the U.N. High Commissioner for Human Rights, Louise Arbour, sent a mission to Nairobi on Wednesday to investigate allegations of "grave human rights violations committed in Kenya in the recent weeks," her office said in a statement.

The mission will speak with victims and witnesses, government and opposition officials, civil society representatives and others during its 3-week stay in Kenya, Arbour's office said.

U.N. Undersecretary-General for Humanitarian Affairs John Holmes is scheduled to arrive in Kenya on Friday for a 3-day visit to assess the humanitarian situation there, Holmes' office said in a statement.