Sudan says that fighting in two states along its disputed border with South Sudan has left over 600 people dead over the past 16 months, releasing rare casualty figures in an ongoing conflict that has inflamed tensions between the two countries.

Interior Minister Ibrahim Mahmoud told the Sudanese parliament Tuesday that 662 people had been killed in South Kordofan and Blue Nile states, where rebel forces are battling government troops, since fighting broke out in June 2011. The minister's comments were quoted by the daily paper Al Sahafa on Wednesday.

Mahmoud said that the military and police sustained heavy losses in battling the insurgency, but did not break down the figures between civilian, government, and rebel casualties.

The fighting pits the Khartoum government against rebel groups allied with the guerrilla forces that eventually came to power in South Sudan, but were left on the north's side of the border after the south became independent in July 2011 according to a deal that ended decades of civil war.

It broke out first in oil-producing South Kordofan shortly before South Sudan's declaration of independence, then spread to neighboring Blue Nile state. Rights groups have reported government bombings of villages in the Nuba Mountains region of South Kordofan during the fighting. The Sudanese government has denied bombing civilians in its Nuba Mountains campaign.

A spokesman for the rebels told The Associated Press by phone that his group rejects the figures. "The government of Sudan is continuing to lie and give false information," said Arnu Lodi of the Sudan People's Liberation Movement-North, questioning the government's ability to gather statistics on the fighting. He declined to provide any casualty figures of his own.

Khartoum says the SPLM-North fighters are backed by South Sudan, an accusation the Juba government denies.

The United Nations estimates that nearly 700,000 people have been displaced or severely affected by the fighting in the two over the past fifteen months. More than 200,000 alone have fled to neighboring Ethiopia and South Sudan.

Since the fighting began more than a year ago, access to the remote region by the United Nations and international aid agencies has been restricted by the Sudanese government, making it difficult to verify conditions in the area.

Meanwhile, this week the parliaments of Sudan and South Sudan both ratified an agreement signed by the two countries' presidents last month in the Ethiopian capital. The deal calls for a cessation of all hostilities that brought the countries to the brink of all-out war earlier this year. The deal enables the resumption of oil exports from South Sudan, which the Juba government suspended in January in a dispute with Khartoum over transit fees for southern oil.

Also, an ambush by unknown assailants killed a U.N.-African Union peacekeeper in the western region of Darfur, the mission said, bringing to 43 those killed in the region since the mission started its work in 2007.

UNAMID said in a press release that three others were wounded in the ambush Wednesday in North Darfur state as a convoy was on its way to assess reports of violence in the region of Habasha North.

The release said UNAMID personnel came under a combination of automatic and mortar fire by unidentified assailants. It called on the government of Sudan to investigate the incident and bring the perpetrators to justice.

At the United Nations, the Security Council issued a statement condemning the attack "in the strongest terms" and called on the Sudanese government to "swiftly investigate and bring the perpetrators to justice."

Sudan's government has been battling rebel groups in Darfur since 2003. More than 300,000 people have been killed in the conflict.

Four Nigerian peacekeepers were killed and eight wounded in an ambush in Sudan's restive West Darfur region on Oct. 2.


Associated Press writer Maggie Fick contributed reporting from Cairo and Associated Press writer Ron DePasquale contributed from the United Nations in New York.