Israeli troops step up security

Israel Arrests More Palestinians

On Friday, the Israeli army said that 51 Palestinians had been arrested "on suspicion of a link to hostile terrorist activity." The operation was described as "widescale" with the aim of locating what were called "incitement materials."

One of the commanders of the operation, identified only as Lt.Col. Guy for security reasons, told Israel Radio that the troops had acted in areas where Israel has ultimate security control under the terms of the peace treaty with the Palestinians.

Mr Ross had been due to leave for the region on Wednesday, but postponed his trip after the attack. US officials say Mr Ross's priority will be to urge greater security co-operation between the Palestinians and the Israeli authorities.

Israel has strongly criticised Yasser Arafat's Palestinian Authority for not doing more to prevent bomb attacks. An aide to the Prime Minister, Binyamin Netanyahu, reiterated Israel's determination to seize "terrorists" if the Palestinian Authority failed to do so.

Palestinian human rights activist Bassam Eid tells the BBC that the Palestinian Authority "has done enough"

Mr Netanyahu accused Mr Arafat of having done "damn all" to root out militants in the Palestinian areas. "I think the Palestinian Authority has had a very free ride," Mr Netanyahu said. "Basically, the line was that that what they do is okay, and the obstacle to peace is on this side."

Jebali, the Palestinian police chief wanted by Israel

The Palestinian police chief, Ghazi Jebali, warned Israel that extending its operations into areas under Palestinian control would amount to a declaration of war. Israel has issued a warrant for his arrest, alleging that he encouraged attacks on Jewish settlements.

It is not yet certain who carried out the Jerusalem bombing. A leaflet purporting to come from the militant Islamist group, Hamas, said it was responsible. But Israel has cast doubt on the claim.

The security forces in Israel remain on high alert against the possibility of further attacks.