One of the murals vandalized was this Banksy work on the side of a Bristol sexual health clinic. Seen in 2006, the mural shows a woman and her jealous husband at a window as her naked lover dangles from the ledge. (Matt Cardy/Getty Images)

Two murals that popular British graffiti artist Banksy painted in his hometown of Bristol were targeted by vandals this week.

The artist's work was splattered with blue paint, believed to be from a paintball gun, on Monday evening.

One of the defaced murals is among the artist's best known: painted on the side of a sexual health clinic, it depicts a naked male adulterer hanging from a window ledge while a man and his lingerie-clad wife peer out.

The other damaged work, known as The Mild Mild West, depicts policemen advancing toward a cartoon bear clutching a Molotov cocktail.

It has previously been targeted by vandals, most recently in April, with a community group regularly stepping up to restore the mural.

Both works are favourite landmarks among area residents. City council vowed to restore the damaged murals.

Banksy, a multimedia artist who gained fame for creating guerrilla artwork that includes thought-provoking graffiti murals spray-painted or stenciled in public spaces, opened a massive exhibit at the Bristol City Museum and Art Gallery earlier this month.