Peacekeepers attacked in Darfur

The UN-African Union force has 15,000 troops in Darfur

Four members of the peacekeeping force in the Sudanese region of Darfur have been injured in an ambush.

It is the first attack on the Darfur peacekeepers since the International Criminal Court indicted President Omar al-Bashir for war crimes last week.

One of the soldiers is in a serious condition following the assault by unknown gunmen near Geneina town.

Meanwhile, the US embassy in Khartoum said it was allowing all non-essential embassy staff to leave the country.

"This is one step down from an ordered evacuation of non-essential staff," an unnamed US official told Reuters news agency.

The official reportedly said it was partly a diplomatic move in reaction to last week's expulsion of 13 aid agencies from Darfur in the wake of the warrant for Mr Bashir.

A spokesman for the joint UN-African Union mission said Monday evening's attack on the peacekeepers marked a worrying escalation of the violence in Darfur.

"We are in Darfur to keep the peace and this is totally unacceptable," Noureddine Mezni told Reuters news agency.

"They opened fire without warning. It could have been fatal," said another spokesman for the force, Kemal Saiki.

"We have no other information about the origin of the attack, or who was behind it," he told the AFP news agency.

As well as pro-government militias and rebel groups, armed criminals have also taken advantage of the breakdown in law and order to operate in Darfur.

The force, known as Unamid, is set to be the world's biggest peacekeeping mission, with 26,000 troops but it currently has just 15,000 - 60% of its intended strength.

Humanitarian fears

Mr Bashir on Sunday made a defiant visit to Darfur and warned all foreign workers to obey Sudan's laws or face expulsion.

The expelled aid agencies have strongly denied Sudanese government claims they have a political agenda.

The UN has said kicking out the humanitarian groups puts more than one million lives at risk.

Some 2.7 million people are receiving aid in Darfur after being forced from their homes.

The UN estimates that 300,000 people have died, since black African rebels took up arms in 2003 against the Arab-dominated regime demanding a greater share of resources and power.

The ICC issued a warrant for Mr Bashir on 4 March, accusing him of two counts of war crimes and five crimes against humanity in Darfur.

It is the court's first indictment against a serving president.

Mr Bashir has always denied that his government helped mobilise the Janjaweed militias accused of the worst atrocities against civilians.

Sudan, the African Union and the Arab League have all urged the UN Security Council to use its powers to defer the arrest warrant, saying it could further destabilise Darfur.

After meeting Mr Bashir in Khartoum on Monday, AU Commission chairman Jean Ping said: "It is clear that the decision of the ICC undermined and jeopardised... reconciliation in Darfur."

But correspondents say the US and UK are unlikely to agree.