A police statement said on Friday told: "Police were summoned to a mosque in Beit Safafa, in Jerusalem, following a report of arson in one of the building's rooms and spraying of graffiti on a nearby wall outside the building."
Israeli police launched a manhunt after an apparent arson attack, accompanied by Hebrew-language graffiti, on a mosque in occupied East Jerusalem.
Nobody was injured in the incident, police said. There was damage to an interior prayer room, but the structure was unharmed.
"A wide-scale search is taking place in Jerusalem," police spokesman Micky Rosenfeld told AFP news agency.
"We believe that the incident took place overnight. We are searching for suspects."
The spokesman would not say if police viewed it as a hate crime. The graffiti, seen by an AFP journalist, contained the name Kumi Ori, a small settlement outpost in the north of the Israeli-occupied West Bank.
One part read, "Demolishing (for) Jews? Demolishing enemies!", an apparent reference to the dismantling of settler outposts in the West Bank.