The bomb attack against an Israeli school bus in Gaza is the first serious violence since the Israeli-Palestinian peace agreement was signed last week.

President Clinton and his officials - whose efforts had made the accord possible - must have been bracing themselves for trouble.

The peace process has many enemies. Hardline Israelis are against the uprooting of Jewish settlements in areas which are handed over to Palestinian control.

Palestinian hardliners, particularly supporters of Hamas, see the peace process as a sell-out of their rights, arguing that the whole of Palestine - not just Gaza and the West Bank - is theirs by right.

Hamas message

The Hamas leader, Sheikh Ahmad Yassin, has refused to say whether the group was behind Thursday's attack. But Israel Radio has played a recording of a telephone call saying Hamas was responsible.

There is a division of responsibility within Hamas between its political and military wings. This enables the group's political leaders to distance themselves from acts of violence.

Hamas has carried out a string of suicide bombings against Israeli targets since the first Israeli-Palestinian peace accord was signed in Oslo five years ago.

If it was indeed behind the attack, its message seems clear - that no peace process worthy of the name can leave Israeli settlements in Palestinian areas, and that as long as the settlers are there, they will not be safe.

Settler anger

The attack will enflame Israeli public opinion just as the Israeli prime minister, Binyamin Netanyahu, is trying to build up support for the agreement he signed last week.

Even before the attack, Israeli settlers were accusing him of treachery by agreeing to hand over more territory to the Palestinians. Now they have more ammunition to use against him.

A spokeswoman for settlers in Gaza has said it was a miracle that none of the children in the school bus were hurt.

Many Israelis will ask, yet again, why the signing of peace agreements seems to decrease rather than increase their sense of personal security.

Palestinian security plan awaited

The implementation of last week's peace accord is due to begin on Monday.

Mr Netanyahu has already said he will not ask his cabinet to approve the agreement until the Palestinians fulfil their pledge to give the Americans a working paper on security.

Desperately anxious to maintain the agreed timetable, the Americans are saying they expect to have the Palestinian plan by Friday.