Masked Palestinian protestors help an injured comrade during clashes with Israeli security forces at the Hawara checkpoint, south of the West Bank  city of Nablus. AFP

Reuters/Gaza/Jerusalem

An Israeli air strike killed a Palestinian mother and daughter in Gaza on Sunday and police said a Palestinian detonated an explosive in her car on a road to Jerusalem, injuring herself and a policeman.

Palestinians disputed the police account, saying an electrical fire in the vehicle was mistaken for a bomb blast.

Four Israelis and 23 Palestinians have died in 12 days of bloodshed fuelled in part by Muslim anger over increasing Jewish access to the al-Aqsa mosque compound in Jerusalem. Violence, including a series of stabbings, has spread from the holy city and the Israeli-occupied West Bank to Israel's interior and Hamas-ruled Gaza.

With Prime Minister Benjamin Netanyahu cautioning Israelis there would be no "quick fix", there was scant sign of any significant moves to turn away from conflict that has raised fears of a third Palestinian uprising.

Palestinian medical officials said 37 Palestinian protesters were wounded by gunfire from Israeli troops during clashes on Sunday in the West Bank.

Responding to cross-border rocket attacks, Israel said its aircraft targeted a Hamas facility in the Gaza Strip. Palestinian medical officials said a pregnant woman and her three-year-old daughter living nearby were killed.

On a West Bank road leading to Jerusalem, police pulled over a car driven by a Palestinian woman who they said shouted "God is great" and detonated an explosive when an officer approached. The woman suffered burns to 40 percent of her body, Jerusalem's Hadassah hospital said, and the officer also was hurt.

A return to bombings, a hallmark of a second Palestinian uprising from 2000-2005, would mark a significant turning point in the current violence.

Rafi Cohen, a police commander, described the vehicle as a car bomb and said "the woman terrorist who drove the vehicle intended to reach Jerusalem".

 No known links to militant groups

But Israel's internal security agency, the Shin Bet, later  said that the 31-year-old woman had no known links to militant groups and had used "flammable materials" to cause a single gas canister to ignite when the policeman approached.

"We are not talking about an explosive device," the agency said in statement, while adding that the woman was carrying handwritten notes "praising martyrs" - a term Palestinians use to describe brethren killed in the conflict with Israel.

A source in the Palestinian security services said there had been "a malfunction in her car, and there was no bombing". The source did not say how that information was gleaned.

Against a backdrop of Muslim protests over Jewish visits to the al-Aqsa plaza, Islam's third holiest site and also revered by Jews as the site of biblical temples, Palestinians have been attacking Israelis with knives, rocks and, on at least one occasion, guns.

Palestinians regard the increasing trips over the past year by Jewish groups and right-wing lawmakers to the compound in Jerusalem's walled Old City as eroding traditional Muslim religious control there.

Israel has said it has no intention of allowing any change to the status quo under which Jews are allowed to visit the site but non-Muslim prayer is banned.

Tensions have also been stoked by Palestinian frustration over the failure to make progress - amid Israeli settlement-building in the West Bank - toward statehood in peace talks with Israel. Those negotiations collapsed in 2014.

Palestinians seek a state in the West Bank and Gaza with East Jerusalem -- which includes the Old City -- as their capital. Israel captured all three areas in the 1967 Middle East war. It withdrew soldiers and settlers from Gaza in 2005.