Israeli tank attack blows holes in a fragile truce

Israel's armed forces fired tank shells into the West Bank city of Nablus and briefly seized control of a Palestinian hilltop during a day of violence that brought the month-old ceasefire brokered by the CIA to the verge of collapse.

Witnesses said more than 10 shells slammed into two police checkpoints, killing one officer, as Israel's army resorted anew to the use of heavy weapons in retaliation for assorted Palestinian shooting attacks on Israeli motorists in the occupied territories.

The shelling followed a week that has seen a slide back towards bloodshed, underlining the ceasefire's ineffectiveness and further corroding the still-unimplemented peace proposals of the American-led Mitchell Committee. One violent incident has followed another in quick succession, raising the temperature in the region and deepening speculation that a larger military conflict is looming between Israel and Yasser Arafat's Palestinian Authority.

The violence includes a thwarted attempt by a Palestinian guerrilla to bomb the Israeli town of Afula, a Palestinian woman being shot dead in a taxi by Israeli soldiers, the large-scale demolition by Israelis of Arab homes, and prolonged battles in the Gaza Strip.

The troubles began when Palestinian gunmen wounded two Jewish settlers – shooting one in the head – in a drive-by attack close to a nearby Israeli settlement near Nablus. The victims' six-month-old child was hurt by flying glass. Furious Jewish settlers, who have been demanding that Ariel Sharon, the Prime Minister, unleash far more of Israel's military might against the Palestinians, responded by stoning Palestinian cars and burning down Arab olive groves. Soon afterwards, Palestinian gunmen severely injured an Israeli motorist at Kiryat Arba, close to Hebron in the southern half of the West Bank.

Israel lashed back by shelling Nablus, a hotbed of resistance to Israeli occupation, killing a 22-year-old policeman and taking control of another hill overlooking the Palestinian city for several hours. Israel has continued to use tanks in Gaza, but it has drastically reduced its rocket and missile assaults against towns in the West Bank since the ceasefire was agreed, so yesterday's operation marked a new deterioration.

None of it bodes well for the mission of the latest American envoy who has arrived in the region in an attempt to save it from an even more serious crisis. David Satterfield, deputy assistant secretary of state for the Near East, who flew to Israel yesterday, is expected to press Mr Arafat to enforce a week of "significantly reduced" violence. After this is completed, America then intends to turn its attention to Mr Sharon and urge him to apply the next stage of the Mitchell report – the "confidence-building measures", which include a full freeze on the building of settlements. Mr Sharon has insisted he will not negotiate "under fire", and wants a complete end to all Palestinian attacks – a position viewed by America as unrealistic.

A senior Palestinian official said: "The situation is going to get far worse unless the Americans are willing to get Sharon to begin implementing the Mitchell report. He needs to understand that Yasser Arafat has called for an end to violence, but he does not completely control Hamas and other militants, or the areas of the occupied territories under Israeli military control."

But talk of the Mitchell proposals seemed fanciful yesterday, given the situation at ground zero. Relations between both sides are dismal – as was emphasised on Wednesday by a bilateral security co-operation meeting that fell apart almost as soon as it started, amid angry allegations of truce violations.

Angry residents of Nablus were mourning the death of the policeman, Mohammed Abu Fayyad, 22, which comes less than two months after 11 Nablus policemen were killed when an Israeli F-16 bombed their headquarters.

A Palestinian spokesman, Nabil Aburdeneh, called the shelling a "very serious escalation" and issued a new appeal to the international community to intervene to enforce the ceasefire. Israel – which has seen 27 of its citizens killed while driving through the occupied territories during the intifada – insisted it was acting in self defence. "We have to do what is necessary," said Danny Seaman, an Israeli spokesman.