Authorities questioned witnesses yesterday in the killing of a U.S. diplomat shot in a drive-by attack as he returned from a New Year's Eve party in the Sudanese capital. The United States sent its own investigators to the country.

One woman said she rushed to help the badly wounded American, who pleaded, "I am dying, I need help," the independent Al-Rai Al-Amm newspaper reported.

John Granville, 33, an official for the U.S. Agency for International Development, was being driven home about 4 a.m. Tuesday when a vehicle cut off his car and opened fire before fleeing, the Interior Ministry said. The diplomat's driver, Abdel-Rahman Abbas, was also killed.

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Granville, who was hit by five bullets but initially survived, died after surgery, said Walter Braunohler, a public affairs officer at the U.S. Embassy in Khartoum.

Sudanese officials insist the shooting was not a terrorist attack, but the U.S. Embassy said it was too soon to determine the motive. There has been no claim of responsibility.

Attacks on foreigners are rare in Khartoum, where a U.S. envoy was last killed in 1973.

In Washington, the State Department said investigators from its Bureau of Diplomatic Security and the FBI were heading to Khartoum, a routine measure when U.S. officials are killed in uncertain circumstances overseas.

"They will be sending a joint team to Sudan to investigate the murders, collect any evidence they possibly can, work closely with the Sudanese government to determine who is responsible for these murders, and bring them to justice," spokesman Sean McCormack said.

The acting U.S. charge d'affaires in Khartoum, Roberto Powers, met with Foreign Minister Deng Alor to review developments in the probe.

Maj. Gen. Abdin el-Tahir, director of criminal investigations, said little material evidence was found. Some witnesses have given information that could help, he was quoted as saying by the semiofficial Sudan Media Center.

Granville was working to implement a 2005 peace agreement between Sudan's north and south, the U.S. Agency for International Development said.