The kidnapping of two aid workers in Darfur was carried out by gangs seeking money said a Sudanese official on Monday, according to the official Egyptian news agency.

The State Minister for Humanitarian Affairs Abdel-Baqi Gilani's comments came as Irish diplomats arrived in Khartoum to participate in the negotiations for the release of an Irish aid worker and her Ugandan colleague.

The minister did not elaborate.

Ireland's team includes its ambassador to Egypt, Gerry Corr; the director of the Irish aid agency, Brendan Rogers; and an army expert on Darfur, Lt. Col. Ollie Barbour.

About six gunmen seized 32-year-old Sharon Commins of Dublin and her 42-year-old colleague, Hilda Kuwuki, from the Darfur base of the Irish aid agency GOAL. The group said the kidnappers forced the two, and a local security guard, into a vehicle and sped away.

During a police chase, the abductors threw the guard out of the vehicle.

No group has yet claimed responsibility for their abduction.

"The security forces and police are looking for signs of the abductors" and soliciting the help of local tribal leaders, Foreign Ministry official Ali Youssef told the Associated Press.

This is the third kidnapping of foreign humanitarian workers in Sudan's remote western region since March, when an international court issued a warrant for the country's president on charges of orchestrating war crimes there.

Officials said the first kidnapping was carried out by a group seeking to retaliate for the arrest warrant against the president.

The silence of the abductors so far follows the pattern of previous kidnappings in Darfur, Youssef said, adding that the government would not use force to release the hostages.

The series of abductions, along with Sudan's expulsion of 13 international aid agencies in response to the arrest warrant, has struck a blow to the vital aid effort in the remote desert region, now in its sixth year of conflict.

Sudan's Arab-dominated government has been battling ethnic African rebels in Darfur since 2003.

Up to 300,000 people have been killed and 2.7 million have been driven from their homes.