LONDON — Police in London have arrested a fifth suspect on suspicion of punching two women on a bus because they are lesbians.

Authorities didn’t identify the victims in the May 30 attack. But Melania Geymonat posted an image on her Facebook page showing her bloodied face and that of her girlfriend’s.

Geymonat said in the post that they were on the upper deck of the bus when a gang of “hooligans” demanded that they kiss. The women tried to reason with them, but the incident escalated.

Police said Saturday all of suspects are between 15 and 18 years old.

Detective Superintendent Andy Cox says that while attacks like this are rare on London buses, extra uniformed and plain clothes officers will be out on patrol this weekend to offer reassurance.