Martin Indyk, chief US negotiator for Israeli-Palestinian talks, has resigned, State Department officials say.
The US Middle East peace envoy resigned on Friday after the two sides failed to meet their goal of reaching a comprehensive peace agreement.
Indyk's resignation was widely expected. He will return to the Washington-based Brookings Institution think-tank, a US official told Reuters news agency.
Al Jazeera's Jane Ferguson, reporting from Ramallah, said Indyk's resignation was no surprise in the Palestinian territories as issues such as the expansion of Israeli settlements in the territories, and the release of Palestinian prisoners had proven too difficult for either side to overcome. Palestinian leaders also signed 15 international treaties in a move that angered Israel.
"The deadline for the talks was the end of April but essentially the talks collapsed well before then so his resignation is no surprise to people here," Ferguson said.
The announcement of the resignation comes against the backdrop of renewed tensions in the territories.
An Israeli air raid on Friday killed two Palestinians and critically wounded a third in the Gaza Strip, medical officials in the Hamas-ruled Palestinian territory said.
The attack targeted a car travelling along a coastal road near a beach refugee camp in Gaza, Reuters news agency reported quoting witnesses.
One source identified the men as belonging to the Popular Resistance Committees, a network of armed Gaza-based Palestinian groups that has been responsible for firing rockets into southern Israel in the past.
An Israeli military spokeswoman said she was checking the report.
Israeli tank fire
In earlier violence on Friday, several Palestinians were wounded by Israeli tank fire near the southern part of the Israel-Gaza border, medical officials and the Israeli army said.
They included an 11-year-old boy who was in serious condition.
Ashraf al-Qudra, a spokesman for Gaza's health services, told AFP news agency that five Palestinians were wounded when the tanks targeted "two mosque minarets" east of Khan Younis, in southern Gaza.
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The Israeli army said its troops near the border fence had been targeted by an explosive device and tanks responded with "fire towards lookout posts used to guide the attack against the forces".
Palestinian fighters from Gaza have launched several rocket attacks into Israeli territory in the past two weeks and Israel has bombed targets in the territory, including training grounds allegedly belonging to armed factions.
An army spokeswoman told AFP that nine explosive devices were set off at Israeli forces near the border with Gaza since the beginning of the year.
Friday's violence comes a day after Israel announced the names of two men it said was suspected of involvement in the disappearance of three Israeli settlers in the occupied West Bank.
Marwan Qawasme and Amar Abu Aysha, both Palestinians from the West Bank city of Hebron, had previously served time in Israeli jails, Reuters said.
Israel scaled back its house-to-house searches for the missing young settlers on Tuesday after arresting several hundred Palestinians.