HUMAN rights campaigners today called on Blackburn residents to write to MP Jack Straw to ensure action is taken to tackle Sudan's humanitarian crisis.

Amnesty International has written to the Blackburn MP and Foreign Secretary -- due to fly out to the struggling African country today -- asking him to investigate claims of human rights violations in the Darfur region of Sudan.

The group claims that Arab militias are killing thousands of the largely black African population.

More than a million refugees have fled the war-torn region following the attacks, with 180,000 crossing into neighbouring Chad, which has strained its resources.

Mr Straw is set to meet government leaders on Monday and then visit a refugee camp in northern Darfur the following day. Foreign Office officials said the United Nations Security Council was reluctant to impose "heavy-duty sanctions" such as an oil embargo or travel bans on Sudanese ministers.

But Amnesty bosses, who briefed Mr Straw last week ahead of his visit, say he needs to put pressure on the Sudanese government to take action against the militia.

Amnesty International UK Director Kate Allen said: "Jack Straw must use this critical opportunity to make it starkly clear to the Sudanese government that the international community will not tolerate continuing atrocities in Darfur.

"Mr Straw's message should be that rape, torture and murder absolutely must be stopped and that perpetrators need to be brought to justice. And we would call on people to support us."

A spokesman for the Foreign Office said Mr Straw's role this week would be to assess how the government in Sudan is dealing with the crisis.