4: RAMALLAH

Then, in a major new escalation of Mideast violence, Israelis kill Mustafa Zibri, a top Palestinian leader. The 63 year-old chief of the Popular Front for the Liberation of Palestine (PFLP) dies at his desk as Israeli helicopters fire laser-guided missles directly into his office windows. So precise are the missles is that the window frames are unharmed, and five others are only slightly injured by flying glass.

As word spreads, gunfire breaks out throughout the West Bank and elsewhere. An Israeli police spokesman tells the UPI wire service, "Every minute there is shooting somewhere else. There is no place where there is no fire now, almost every road, every position."

The Palestinians call it an assassination of one of their foremost leaders. Thousands of Palestinians pour on to the streets of the West Bank city of Ramallah vowing revenge. The PFLP is the second largest group in the PLO, outranked only by Yasser Arafat's own Fatah. The PFLP is not associated with the Democratic Front for the Liberation of Palestine, which attacked an Israeli army base two days ago.

Israelis say that Zibri was a "car bomb specialist" and justify killing him as part of Israel's "active self-defense" policy. "Whoever hits us and plans attacks and carries them out will be hit. This is our duty," a defense official tells the Jerusalem Post.

UN Secretary-General Kofi Annan denounces the attack, saying Israel has raised "tensions in the region to levels we have not seen in many years" The Palestinian Authority says Zibri's killing sets the stage "for a full-scale, unlimited war" and tells the UN that Israel is trying to undermine peace negotiations.

Several Palestinian spokesmen remark that the Bush administration has sanctioned such violence by supporting Israeli Prime Minister Ariel Sharon. The U.S. response to the killing is a tepid statement that the State Department is "deeply troubled" because there were 20 American citizens elsewhere in the same building where Zibri was killed.