Russia and China blocked US attempts to get the UN Security Council to condemn Sudanese government bombing and other military activities in the South Kordofan region of Sudan, UN diplomats said.

South Kordofan lies across the border from newly independent South Sudan, and the clashes between government troops from Sudan’s Arab north and forces aligned with the south have added to the strained relations between the two countries.

The United States circulated a statement earlier this week which would have condemned the violence in South Kordofan and called for an end to the aerial bombings.

But the diplomats, speaking on condition of anonymity because discussions were private, said the US withdrew it on Friday because of Russian and Chinese opposition to any condemnation or mention of aerial bombing.

Both countries are allies of Sudan, and China is a major arms supplier and a heavy investor in Sudan’s oil industry.

US Mission spokesman Mark Kornblau said: “The grave humanitarian situation in South Kordofan demands a clear and strong response from the Security Council, not a watered-down statement.”

Many inhabitants of South Kordofan fought for the south during the country’s more than two decade civil war against the north and are ethnically linked to the south.

Thousands of soldiers in the southern army hail from the fertile and militarised Nuba Mountains in South Kordofan, whose people practice Islam, Christianity and animism.

The government in Khartoum insists it is not targeting civilians