A Jewish-Arab bilingual school and a Christian monastery in Jerusalem were defaced with graffiti on Tuesday in suspected "price tag" attacks carried out by Jewish extremists.

"Death to Christians" was daubed in Hebrew on the outer walls of the Monastery of the Cross, an 11th century fortress-like holy site situated in a valley overlooked by Israel's parliament.

This monastery in Jerusalem was built on the spot where, according to tradition, the tree from which Jesus's cross was made once sat,

Police spokesman Micky Rosenfeld said the words "price tag" were also painted on the Christian monastery overnight by vandals, in the rare attack on a Christian shrine in Jerusalem.

The slogan, used by Jewish settlers in vandalism attacks on mosques and Palestinian homes in the West Bank, refers to the retribution they say they will exact for any attempt by the Israeli government to curb settlement in the territory.

"I am a priest and I forgive," Father Claudio of the monastery, which is administered by the Greek Orthodox church, said.