The head of Russia's Bolshoi ballet Sergei Filin was Friday hospitalised with severe burns after a masked assailant threw acid on his face, in an attack the theatre linked to internal conflicts.

Filin, a former acclaimed dancer who was appointed to his post in 2011, suffered injuries to the face, head and eyes late Thursday when the attacker cornered him near a residential house in central Moscow.

"I got scared, I thought he is going to shoot me," said the 42-year-old, sitting in a Moscow hospital room with his face almost totally bandaged talking with the Ren-TV channel.

"I turned around to run, but he raced ahead of me," he said. The attacker had his face in a mask and wore a hood, Filin said. "Only his eyes (were visible)."

The assailant fled the scene and no suspects have been identified so far, police said. However both police and his colleagues had little doubt that Filin was targeted because of his professional work in the Bolshoi.

"This is clearly tied to his professional activities," said Bolshoi general director Anatoly Iksanov.

"I really hope that the person who ordered (the attack) is found," Iksanov added. "This person is a monster."

Doctors are currently battling to save Filin's eyes, he said. "The eye operation is about to start," he told journalists at the theatre. "Then he will be sent to a military burn hospital in Belgium."

Filin took charge of Bolshoi ballet in 2011 and is an integral part of the theatre's recent artistic remake, turning more away from classical repertoire toward innovative and modern productions.

Filin has been a subject of harassment for some time: his website and email were hacked, and somebody punctured the tires on his car, Iksanov added.

Speaking with Ren-TV, Filin said he was also harassed on New Year's Eve, with people repeatedly placing calls on his mobile and completely blocking his communication.

Police launched a probe into malicious damage to a person's health, a crime that could lead to eight years in prison.

The latest brazen attack shocked the ballet community and traumatised the Bolshoi troupe, although some observers noted that the theatre has always been plagued by internal conflicts.

"We are shocked and shaken, this is hard to fathom," said the Bolshoi's best known current prima ballerina Svetlana Zakharova. "We didn't sleep all night," she said.

"Sergei is a good director, he had everything under control."

One of Filin's predecessors, Alexei Ratmansky, who left Bolshoi in 2008 and is now a choreographer at the American Ballet Theatre, said what led to the attack was the Bolshoi's "lack of theatre ethics."

"The tragedy with Sergei Filin is not a coincidence," he wrote on Facebook, listing the "disgusting" practise of hiring people to applaud at performances, the theatre's unresolved issue of ticket scalpers, and scandalous press interviews by troupe members as some of the issues plaguing the establishment.

"What happened shocks everyone, but it doesn't surprise that many people," Russian ballet historian Vadim Gayevsky told AFP.

Even in Soviet times, Bolshoi dancers spiked each others' pointe shoes with crushed glass, while legendary Soviet prima ballerina Galina Ulanova received threatening letters, he said.

Filin is a popular figure said to be adored by the dancers but the Bolshoi ballet remains hugely influenced by its chief ballet master, the veteran Soviet choreographer Yuri Grigorovich, and apparently driven by internal conflict.

Male dancer Nikolai Tsiskaridze, one of the Bolhoi's most visible stars due to appearances on TV shows, had meanwhile complained of not being given enough chance to dance performances under Filin's tenure.

The biggest public scandal on Filin's Bolshoi watch was the late 2011 exit from the institution of its star real-life couple Ivan Vasiliev and Natalya Osipova, who left Moscow to dance at a lesser known theatre in Saint Petersburg.

In a sign of the internal troubles at the theatre, one of the dancers contending for Filin's current post was in 2011 targeted by a porn smear scandal that effectively ruined his chances.