Story highlights The mosque entrance was set alight, Palestinian official says

The vandals spray-painted the words "revenge by blood" on the mosque, he said

The Israel Defense Forces says it was a so-called "price tag" attack

It was an apparent response to clashes last week between Jewish settlers and Palestinians

Israeli Jewish settlers set the entrance of a West Bank mosque on fire and spray-painted the mosque walls with hate messages against Palestinians and Muslims early Wednesday, Palestinian officials said.

The attack in the village of Deir Istiya was an apparent response to an incident last week in which Israeli settlers, Palestinians and Israeli forces clashed near the village of Qusra, south of Nablus.

"This is not the first time extreme Jewish Israeli settlers set a mosque on fire in the West Bank village of Deir Istiya and spray-painted hate messages," said Ghassan Douglas, a Palestinian Authority official who monitors the activities of settlements and settlers in the West Bank.

"The settlers almost on a daily basis do this to isolated Palestinians and damage their properties."

Douglas said the incident was a so-called "price tag" attack -- a term used to describe acts of vandalism by radical Israeli settlers exacting a "price" against Palestinian targets or Israeli security forces in response to actions by the Israeli government.

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The vandals spray-painted the words "revenge by blood" and "Qusra" in a reference to last week's incident, Douglas said.

The past two years have seen an increase in extremist Israeli Jewish settler attacks against Christian and Muslim religious sites, in which churches or mosques have been set alight, and against Palestinian property.

The Israel Defense Forces confirmed that a "price tag" incident had occurred, in which the door to the mosque was damaged and a rug was burned.

Graffiti was sprayed on the walls saying "Arabs out" and "regards to Qusra," the IDF said.

IDF spokesman Peter Lerner condemned the act.

"The incident is deplorable on every level," he said. It's against basic moral standards and jeopardizes safety and security and the stability the IDF is working hard to maintain."

He said the IDF is taking the incident "very seriously" and is determined to prevent a recurrence.