GAZA (Reuters) – Palestinian militants in the Gaza Strip kept up rocket and mortar fire on Israeli targets on Monday despite Palestinian President Mahmoud Abbas”s vow to do his utmost to prevent further attacks.

The latest salvoes, which caused no damage or casualties, had diminished in intensity from the past few days which were marked by heavy barrages that prompted Israel to mass tanks at the Gaza frontier and threaten a large-scale ground offensive.

Both sides were under growing pressure to defuse the crisis, the worst bloodshed since a truce took effect in February, before it might disrupt Israel”s planned withdrawal from the occupied Gaza Strip next month.

Egyptian mediators were meeting militant leaders in Gaza in an attempt to keep the ceasefire from collapsing entirely.

Secretary of State Condoleezza Rice scheduled a quick trip to the region this week to try to keep the Gaza pullout on track, as Israeli Prime Minister Ariel Sharon appeared headed for a showdown with rightist protesters opposed to his &#34disengagement&#34 plan.

Abbas promised on Sunday to do &#34all we can&#34 to prevent further rocket strikes on Israelis &#34regardless of the price.&#34

But on Monday the Islamist faction Hamas and other groups fired about a dozen mortars at Jewish settlements in Gaza and at least one makeshift rocket into southern Israel, the army said.

There have been more than a hundred such cross-border attacks since last week, including one that killed a young Israeli woman on a collective farm on Thursday.

Hamas says it is avenging Israel”s killing of militants, including eight of its gunmen since last Friday in a renewed assassination policy against top Palestinian fighters.

&#34We will continue to bombard the enemy with rockets and bombs until they are removed from all of our occupied land, defeated and humiliated,&#34 Hamas, which is sworn to Israel”s destruction, said in a statement.

A senior Hamas official said earlier that the group remains committed to the &#34calm&#34 it had agreed with Abbas, but reserves the right to &#34respond to Israeli attacks on our people.&#34

Sharon, who ordered Israel”s army to step up action after a suicide bombing killed five Israelis in a coastal town last Tuesday, told his commanders on Sunday &#34to act without limitation to stop the strikes on Israeli communities.&#34

But Sharon later hinted Israel would not be quick to launch a major incursion into Gaza, telling his cabinet he would &#34weigh our response&#34 to further truce violations.

Abbas accused Israel of undermining his efforts to control the situation. But Israel said it had no choice but to act because Abbas, facing a growing political and military challenge from Hamas, had failed to rein in militant groups.

Sharon has vowed to do whatever is necessary so that Gaza”s 21 settlements are not evacuated &#34under fire.&#34

He appeared headed for a fresh confrontation with settlers and supporters opposed to any pullout. A mass rally was set for the southern town of Netivot on Monday to kick off three days of protests.

Settler leaders say tens of thousands of people will then defy a police ban and march toward Gaza”s main settlement bloc on Wednesday, risking clashes with security forces.

Polls show most Israelis support Sharon”s &#34disengagement&#34 plan, which international mediators see as a possible springboard to renewed peace talks. Some 8,500 Jews live cloistered from 1.3 million Palestinians in Gaza.

Ultranationalist settlers and their supporters say ceding occupied land they see as Israel”s by biblical birthright would be a reward for Palestinian violence. Palestinians want the West Bank and Gaza for a future state.