Who is vandalising Japan's landmarks? Police mystified after oily liquid appears on 33 monuments

Japan is mystified at a series of 33 "malicious" attacks on some of its most famous landmarks spread across nine prefectures - and police are no nearer to apprehending the "hooded" suspect.

Authorities at temples and shrines, primarily in central Japan, first began reporting small amounts of an oily liquid had been sprayed on buildings in early April.

Toji Temple, a listed World Heritage site in Kyoto, was a target, with blotches splashed on the Mieido Hall, a designated national treasure, and a ceremonial gate. Abemonjuin temple and Kashihara Shrine, both in nearby Nara prefecture, have also been affected, along with Nijo Castle in the centre of Kyoto.

Reports of damage have also come from Chiba prefecture, east of Tokyo, Niigata prefecture on the northern coast and Shizuoka, Shiga and Kagawa prefectures.

The National Police Agency has confirmed it is investigating the vandalism.

Masahito Kanetaka, the commissioner general of the force, said prefectural police headquarters have been ordered to step up patrols of properties that might be at risk.