Logie winner Hugh Sheridan has taken to social media after witnessing a series of violent attacks outside a Perth theatre, with his brother and a castmate among the victims.

Key points: Actor Hugh Sheridan said Hair castmate Matthew Manahan was glassed and his brother also attacked

Actor Hugh Sheridan said Hair castmate Matthew Manahan was glassed and his brother also attacked The Adelaide actor said the violent incidents happened after last night's performance of the musical Hair

The Adelaide actor said the violent incidents happened after last night's performance of the musical Hair WA Police said two teenagers were charged over several alleged assaults

The Adelaide actor, who is currently touring as part of the musical Hair, said co-star Matthew Manahan was glassed and his brother was also attacked in the street, as the group was leaving His Majesty's Theatre after last night's show.

"Tonight this kind soul pictured here with me was attacked for no reason, he was glassed in the street," Sheridan wrote on Instagram alongside a picture of himself and Manahan.

"Minutes later my beautiful brother was attacked by the same person just after leaving the theatre with me."

Sheridan said after heading to a local police station, he later witnessed "another senseless attack" in which people were spat on and punched.

Hugh Sheridan and Matthew Manahan are co-starring in the musical Hair. ( Instagram: hugh_sheridan )

Hair is currently two days into an 11-day run in Perth, but Sheridan said he did not know if the incidents would impact on the show's upcoming performances.

"Matt is still in hospital and my understanding is he's still awaiting a CAT scan," Sheridan posted.

"If my brother wasn't there I would've been completely caught unaware."

Hair, a popular and progressive — but sometimes controversial — musical was written in the late 1960s during the Vietnam War, and tells the story of a group of New York hippies opposed to conscription.

Sheridan said its themes were starkly at odds with the violence he witnessed.

"I can tell you now, our amazing tribe have rallied around each other and these events only bring us closer together, it only shows how relevant our story still is and how timely it is for it to be told," he said.

WA Police have confirmed two teenage boys were charged over several alleged assaults, including one in which a man in his 20s was hit in the head from behind with a glass bottle.

The boys, aged 14 and 15, are due to appear in court today, and Inspector Dean Snashall said a "number of incidents" were being investigated.

"A number of disturbances occurred in the Hay and Murray Street Mall between 10:20pm and 10:50pm," he said.

"Both juveniles have been charged with multiple offences.

"There were a number of offices in the area at the time. [Police] responded as a result of footage on the CCTV network from the City of Perth."

Inspector Snashall said investigations into the incidents were ongoing and asked witnesses to contact police.

Organisers of the musical said today's matinee and evening performances would go ahead.