By Opheera McDoom

KHARTOUM, April 13 (Reuters) - Darfur rebels said on Sunday they had attacked an army base in West Darfur, killing a large number of soldiers in a renewal of fighting in the troubled area near Sudan's western border with Chad.

Protests around the world to mark five years of war in Darfur are expected to draw thousands of people later on Sunday.

West Darfur has seen the worst fighting between the Justice and Equality Movement (JEM), Darfur's most militarily powerful rebels, and the government, with more than 100 people killed in clashes in February. Sudan accuses neighbouring Chad of supporting JEM.

"The movement shot at an army helicopter and burnt it completely during the battle, and hit another one although its fate is unknown," JEM said in a statement sent on Sunday.

The attack on Saturday afternoon lasted until the evening and JEM killed "a large number of government troops", the statement said.

The governor of West Darfur Abu el-Gasim confirmed there had been clashes in KishKish between army and JEM troops but said he did not have more details.

Sudan's army could not immediately comment on the report and officials from a joint U.N.-African Union peacekeeping mission, known as UNAMID, were unavailable for comment.

JEM said it had stolen weapons and vehicles from the army.

International experts estimate some 200,000 people have died and 2.5 million been driven from their homes since mostly non-Arab rebels took up arms in Darfur five years ago.

Washington calls the violence genocide and the conflict has captured attention in the West, with Hollywood stars, sportsmen and world famous authors campaigning for an end to fighting.

Khartoum denies genocide, a term European governments are reluctant to use, and puts the death toll at 9,000, blaming the Western media for exaggerating the conflict.

Sunday's international commemoration, backed by celebrities including children's authors Judy Blume and J.K. Rowling and actor George Clooney, is intended to highlight the plight of more than one million children caught up in Darfur's fighting. The protests are being organised by an international coalition of activists and rights groups.

"Days like this matter because they keep what is happening in the eyes of the international community," said Clooney, who is also a U.N. messenger of peace. "We need sustained international engagement if we're to see real progress on the ground."

British Prime Minister Gordon Brown said he would push the U.N. Security Council next week for progress on Darfur. Brown's office said on Sunday he had offered to host Darfur peace talks.

"Like the thousands of people taking part in events across the world today I feel frustrated by this appalling situation and the slow progress, but I am determined that we will not fail," Brown said in a statement on Sunday.

"I will be pushing for UNAMID to be more quickly deployed, the peace process restarted and, all sides to commit to a ceasefire," he added. (Editing by Catherine Evans)

AlertNet news is provided by