US Secretary of State Hillary Clinton and Russian Foreign Minister Sergei Lavrov discussed their “shared concern over the recent violence and continuing inter-ethnic tensions” in Kyrgyzstan, spokesman Philip Crowley said in a statement.

“The ministers agreed that the issue of the upcoming referendum is the sovereign decision of Kyrgyzstan to make and agreed to encourage the authorities of Kyrgyzstan to conduct it according to international standards.”

The pair also discussed “coordination of US and Russian humanitarian assistance and other support to Kyrgyzstan to help its authorities restore security, stability and reconciliation” in their phone conversation.

Officials and aid agencies say the clashes between Kyrgyz and Uzbeks have killed up to 2,000 people and affected up to one million, including 300,000 people displaced in Kyrgyzstan and 100,000 who have fled to neighboring Uzbekistan.

The riots were the worst inter-ethnic clashes to hit the impoverished Central Asian state since the collapse of the Soviet Union.

Victims of the unrest have told AFP that the violence was a brutal and orchestrated campaign by armed militias of ethnic Kyrgyz targeting Uzbeks, who make up 14 percent of Kyrgyzstan’s population of 5.3 million.