Britain condemns Darfur violence
Speaking late on Sunday night, Mr Straw said: "The recent actions by the government of Sudan have been carried out in defiance of the obligations placed upon it by three UN Security Council Resolutions on Sudan.
"If the UNSC receives reports from either the African Union, or its own Secretary General, confirming additional serious ceasefire violations, then we would expect an urgent meeting of the UNSC to be convened to take further action."
Britain's International Development Secretary Mr Hilary Benn, added: "The international community will not stand by while these violations are committed by either the Sudanese Government or the rebels.
"Recent rebel attacks on Tawilla and on humanitarian convoys in Darfur, along with the murder of two Save the Children UK staff are particularly horrific."
Straw says Sudan is defying the UN's will