At least 20 people died in Israel last night when a Palestinian suicide bomber blew up a bus in West Jerusalem. More than 100 people were injured including 40 children.

The New York Times described it as one of the deadliest attacks since the second intifada began three years ago. The bombing marks the most serious blow to the six-week-old ceasefire.

The bus was carrying religious Jews who had been visiting the holy site of the Wailing Wall.

After the bombing, Israel shut the Palestinian border, froze peace negotiations and canceled plans to withdraw troops from four West Bank cities.

There were reports that both Islamic Jihad and Hamas took responsibility for the attack.

In a phone call to the Associated Press, a representative of Islamic Jihad warned that Israel would face retribution “like an earthquake” because Israel had killed one of its top commanders, Ahmed Sidr last Thursday.

The Israeli newspaper Haaretz reports Prime Minister Ariel Sharon is meeting with advisors today to discuss Israel’s response.

Palestinian Prime Minister Mahmoud Abbas condemned the attack and announced he had cut off talks with Islamic Jihad and Hamas.

• Abe Greenhouse, member of the Central Jersey Jews Against the Occupation. He witnessed the bus bombing Tuesday in Jerusalem.