A bomb has exploded on a bus in Tel Aviv this morning, injuring ten people. The Islamic militant group Hamas is claiming responsibility. The Israelis are calling it a “terrorist attack”.

This latest violence is making the task of ending the conflict more difficult. US Secretary of State Hilary Clinton and other diplomats are trying to broker peace between Israel and the Palestinians.

Clinton is in Cairo after a round of talks with Israeli and Palestinians leaders. She will meet with Egypt’s President Mohammed Morsi to try to defuse a week of violence that has left five Israelis and more than 130 Palestinians dead.

Clinton said the U.S. “strongly condemns” what it also calls a “terrorist attack” on the bus in Tel Aviv.

As talks continue, thousands of Israeli troops are massed on the Gaza border, waiting for a possible order to invade.

The UN Security Council will debate the Gaza crisis this afternoon if a cease-fire isn’t reached.