Israel puts pressure on Palestinian leader with attack on Gaza

The Israel Defence Force said last night that the shell fire was intended to "deter" further attacks. No casualties were reported from either the shell fire or the rocket attack ­ the second of the day ­ on the Israeli border town of Sderot.

The shelling followed further air strikes on Gaza and dozens of arrests of Hamas candidates in forthcoming local and legislative elections in the West Bank by the IDF in a second large-scale wave of detentions aimed at militant factions.

The sweep in the Ramallah area, which brings the number detained this week to 379, was criticised by the Palestinian Authority (PA) and cuts directly across the efforts of its President, Mahmoud Abbas, to curb violence by bringing Hamas into the political process. Israel wants Hamas disarmed by military means.

The arrest of a further 82 activists follows Israel's warning that it will "not assist" Hamas's attempt to win seats in legislative council elections next January. Israel wants the group to be banned from contesting the elections unless it disarms.

Ghassan Khatib, planning minister of the PA, said Israeli "interference" was "only complicating the situation for the Palestinian Authority" . The PA fears the move may increase Hamas's popularity and the risk that it will pull out of the elections, further reducing the PA's legitimacy.

Zalman Shoval, a senior adviser to the Israeli Prime Minister, Ariel Sharon, said Israel was trying to make Mr Abbas understand that peace efforts could be frozen if he brought Hamas into government. But Mark Regev, the foreign ministry spokesman, denied that Israel had specifically sought to detain election candidates, "We are arresting Hamas activists because there is perceived to be a significant terrorist threat. It could well be that Hamas activists are also political candidates but that is not our motivation," he said.

Mr Regev pointed to a video released by Hamas yesterday when they claimed responsibility for the abduction and killing of an Israeli businessman, Sasson Nuriel. It shows Mr Nuriel asking for Palestinian prisoners to be released. "This shows what Hamas essentially is," Mr Regev said.

The Hamas attacks followed an explosion last Friday that killed 20 Palestinians. Hamas said an Israeli missile was responsible. The credibility of that claim was further undermined yesterday when a Palestinian interior ministry report said shrapnel in bodies of the victims came from Hamas's home-made rockets, which were being paraded at the time of the explosion.

Mahmoud Zahar, head of Hamas in Gaza, has called a halt to the rocket attacks, while Islamic Jihad, which has been targeted since carrying out two suicide bombings in Netanya and Tel Aviv earlier this year, said it would again honour the ceasefire if Israel halted "its aggression against our people".