The attack left walls charred, books burned and graffiti scrawled on the walls
Israel is investigating Palestinian suspicions that a mosque in the West Bank was set alight by Jewish settlers.
Arsonists reportedly scrawled Hebrew graffiti on the walls of the mosque in Beit Fajjar, near Bethlehem.
The mayor of a nearby settlement condemned the attack and said those carrying it out must have been “extremists”.
The assault comes as Palestinian-Israeli peace talks have faltered over the issue of settlements.
Israel has occupied the West Bank, including East Jerusalem, since 1967, housing nearly 500,000 Jews in more than 100 settlements. Some 2.5 million Palestinians live in the West Bank.
Jewish settlements are illegal under international law, though Israel disputes this.
Residents of Beit Fajjar said a group of settlers went into the mosque overnight and set fire to carpets and copies of the Koran.
Reports say the word “revenge” was scrawled on the wall in Hebrew.
A spokesman for the Israeli military said it was taking the burning of the mosque very seriously.
“We are doing the utmost in order to reach those law-breakers,” army spokeswoman Avital Leibowitz told reporters in Tel Aviv.
Israeli settlements on occupied land
* Nearly 500,000 settlers in the West Bank and East Jerusalem, alongside 2.5 million Palestinians
* 20,000 settlers live in the Golan Heights
* Settlements and the area they take up cover 40% of the West Bank
* There are about 100 settlements not authorised by the Israeli government in the West Bank
Meanwhile Shaul Goldstein, the mayor of Gush Etzion, a local settlement, told the BBC he condemned the attack.
While extremists were present in every society, he said, “they do not represent the entire society. The settlers are against it.”
Previous Israeli investigations of mosque attacks have failed to produce results.
In April, a mosque was vandalised with Hebrew graffiti, cars were burnt and olive trees uprooted in the village of Hawara, near the Yitzhar settlement.
And in May, a mosque in the Palestinian village of Lubban al-Sharqiya, near Nablus, was gutted in a fire which also destroyed holy books.
No charges were brought against anyone in either case.
Mohammad Hussein, the Grand Mufti of Jerusalem, came to inspect the damage and talk to the locals.
“The settlers’ message is: terrorise the Palestinian people,” he told Reuters news agency.
“Crimes like these do not terrorise the Palestinian people. On the contrary, such attacks will only embolden the Palestinian people and increase our determination to achieve all of our rights,” he reportedly said after delivering a brief sermon.
‘Price tag policy’
Some hard-line settlers advocate a “price tag” policy under which they attack Palestinians in retaliation for any Israeli government measure they see as threatening Jewish settlements.
The Palestinian leadership has said it will not continue peace talks with Israel unless a freeze on Jewish settlements in the West Bank resumes, after building started again last week.
Israel refused to extend a 10-month partial ban on settlement building in the West Bank which expired last Sunday.
Direct talks between Israel and the Palestinians resumed in September after a break of nearly two years.