RAMALLAH ø The United States has determined that Palestinian Authority Chairman Yasser Arafat approved an attack on a U.S. embassy convoy in which three Americans were killed in 2003.

In October, a bomb exploded as a U.S. embassy convoy passed through the northern Gaza Strip on the way to a meeting in Gaza City. Three U.S. embassy security guards ø protecting American visitors who were to discuss the Fulbright Program ø were killed in the attack next to the Jabalya refugee camp.

A Fatah-aligned group later claimed responsibility, Middle East Newsline reported. The U.S. sources said the attack was planned and directed by elements within the Palestinian security services.

U.S. diplomatic sources said a U.S. investigation into the bombing of the embassy convoy in the Gaza Strip in October 2003 pointed to a clear role by Arafat. The sources said Arafat granted approval to a plan to strike U.S. interests in PA areas.

Arafat, the sources said, did not draft or approve any details for a Palestinian attack. But they said Arafat agreed to a proposal relayed by a high-level aide for the Palestinians to "pass a message" to the United States.

According to the sources, a senior Arafat aide and member of the Fatah Central Committee left Gaza City for Arafat's headquarters in Ramallah in September 2003 to seek approval for a Palestinian attack on U.S. interests in the area. The Fatah official, described as a liasion between Arafat and Palestinian insurgents in the Gaza Strip, complained of U.S. policy toward the PA and Arabs.

During their meeting, the sources said, the official asked Arafat whether it was time to relay a message to the United States. Arafat was said to have replied, "May God bless this," which translated into "Go ahead," the sources said.

"Arafat did not require or want details of this plan," a U.S. diplomatic source said. "That's not his style. He has always wanted to maintain an element of deniability."

Weeks after the attack, PA security forces arrested and charged four Palestinians with the bombing. But U.S. officials said the defendants were not the actual suspects and in March 2004 they were ordered released by the Palestinian High Court.

[On Monday, Israeli troops foiled a Palestinian insurgency attack on the Israeli community of Netsarim outside Gaza City. The insurgents ø said to come from Fatah, Hamas and Islamic Jihad ø fired mortars, hurled grenades and employed small arms fire in an attempted raid of the community.]

U.S. officials said the failure of the PA to capture the killers of the American security guards has marked a major impediment to U.S.-Palestinian relations. They said the PA was warned that the United States would not approve any funding for the Gaza Strip in the aftermath of a planned Israeli withdrawal.

Palestinian National Security Adviser Jibril Rajoub has been sent to Washington to meet senior U.S. officials to discuss the Israeli withdrawal plan. Rajoub, scheduled to be joined by PA International Cooperation Minister Nabil Shaath, was expected to discuss the PA's role in ensuring security in the Gaza Strip after any Israeli pullout.