HIGHLIGHTS: Large Scale Operation||Refugee Camp, Scene of Recent Atrocities, Partially Spared||Washington Finds No Evidence PLO Involved in Resistance Attacks Against Israel|| Tenet May Shift Security Talks to Washington||STORY: Israeli tanks invaded the Palestinian city of Jenin in the West Bank early Friday, and shooting exchanges broke out, witnesses said. More than 20 tanks and other armored vehicles entered the city from the west at about 3:30 a.m., and soon after, gunfire and explosions were heard, Palestinian residents of the city said. (Read photo caption)

There was no immediate word on casualties and Israeli occupation sources declined immediate comment.

Last week, Israeli troops completed a six-week sweep that targeted Resistance activists in the Palestinian cities and towns of the West Bank.

Israeli occupation forces have continued to make brief incursions to arrest or kill suspected Resistance leaders extra-judicially, but the operation in Jenin appeared to be on a larger scale.

The Jenin refugee camp, which is adjacent to the city of Jenin, was the scene of fierce fighting last month.

Friday's incursion targeted the city, and occupation troops did not immediately enter the refugee camp.

US SAYS NO EVIDENCE OF PLO INVOLVEMENT IN ATTACKS AGAINST ISRAEL

In Washington, a State Department report found "no clear evidence" that Yasser Arafat or other senior officials of the Palestine Liberation Organization planned or approved of terror attacks on Israel between mid-June and mid-December of last year.

"The weight of evidence," however, indicates that senior leaders of the PLO and the Palestinian Authority knew that elements of Arafat's organization, including his bodyguards, were involved in violence against Israel and "did little to rein them in," the department said in a report to Congress.

The report said it was clear that those in the PLO who committed acts of terror were going unpunished, and that there is no system to bring terrorists to justice within the Palestinian organization.

The report dealt with PLO compliance with the 1993 Oslo accords and their requirements that Arafat's organization counter terror.

TENET MAY SWITCH SECURITY TALKS TO WASHINGTON

Meanwhile, CIA Director George Tenet may bring Israeli and Palestinian security experts to Washington for talks on curbing terror, two U.S. officials said.

Tenet has been expected to go to the Middle East to try to revamp the Palestinian security operation. As of Thursday, he had not decided.

Switching security talks to Washington could make it easier for the Bush administration to apply pressure for a radical overhaul in the security situation.

The administration is demanding that the Palestinians establish a unified security system. Strengthening security is an Israeli condition for submitting to U.S. pressure to resume negotiations that President Bush and Powell hope will lead to a Palestinian state on land now controlled by Israel.

PHOTO CAPTION

Palestinian residents sift through the rubble of homes following an incursion by Israeli tanks in Rafah, southern Gaza Strip, Wednesday, May 15, 2002. (AP Photo/Khalil Hamr