The Palestinian militant group Hamas has claimed responsibility for today's (Wednesday's) suicide bombing on a Jerusalem public bus.
Latest reports say the bomber killed 16 Israelis in addition to himself and wounded more than 90 people.
Hamas announced the claim on its website and over loudspeakers to residents in Gaza City.
Witnesses say the bomber was disguised as an ultra-Orthodox Jew. The blast happened on West Jerusalem's main thoroughfare, Jaffa Street, which has been the site of several Palestinian suicide attacks in the past.
President Bush strongly condemned the bombing in comments to reporters in Chicago. The visibly angry Mr. Bush urged all nations to cut off funding to groups such as Hamas, and to isolate those who, in his words, "hate so much they are willing to kill."
Shortly after the blast, Israeli helicopters fired rockets at a car in Gaza City. Witnesses say seven Palestinians were killed, including two members of Hamas's military wing. It is unclear whether the attack was in retaliation for the bus bombing.
Today's violence comes one day after Hamas vowed to avenge Israel's attempt to kill a senior Hamas official, Abdel Aziz Rantisi. Another Hamas official, Mahmoud Zahar, said the bombing in Jerusalem is a message to Israelis that they are not safe anywhere.
Earlier, Israel said it has intelligence proving Mr. Rantisi helped to plan attacks on Israelis. Israeli officials say the evidence shows the attempt to kill Mr. Rantisi was justified, and not intended to sabotage the "road map" plan for peace in the Middle East.
The "road map" plan calls for a series of steps by Israelis and Palestinians leading to the creation of an independent Palestinian state by 2005.