Protesters have disrupted the Israel Philharmonic Orchestra's BBC Proms concert at London's Royal Albert Hall.
Several demonstrators in the hall shouted as Zubin Mehta stood to conduct Bruch's violin concerto. Many other audience members booed in response.
BBC Radio 3 said it had to interrupt its live broadcast twice "as a result of sustained audience disturbance".
The Palestine Solidarity Campaign had earlier called on people to boycott the concert and urged the BBC to cancel it.
In a statement published on its website ahead of the Proms, the pro-Palestinian group claimed the IPO showed "complicity in whitewashing Israel's persistent violations of international law and human rights".
The BBC Proms Team tweeted: "We're sorry that the concert was taken off air following hall disturbance. Glad both pieces were heard by the audience in the RAH."
It later added: "We regret that as a result of sustained audience disturbance tonight's concert was taken off BBC Radio 3."
The performance, which consisted of four parts, was interrupted at about 19:45 BST and coverage was cut off again an hour later after more protests.
A spokeswoman for BBC Proms said it appeared each piece had been targeted by different protesters seated around the hall.
She said the broadcaster was "disappointed" the coverage had been taken off air but said the performance had continued in the hall.
About 30 people were removed by security but there were no arrests and no violence, she said.
The BBC's Tom Symonds said: "As Zubin Mehta stood up and began each piece a small group of protesters each time tried to stop the music.
"They sang, they shouted, they were met by boos by the audience and they had to be removed by the security staff."
Outside the concert hall a group of about 20 campaigners waved banners and sang songs in protest against the appearance of the Israel Philharmonic Orchestra (IPO).
Several pro-Israeli groups met them with their own protest outside, our correspondent said.
He said it had been a "pretty disruptive" but the orchestra was said to have "taken it all in their stride and had smiles on their faces".
Ode to Joy
Regular Proms-goer Chris Keating said there were six or seven disturbances during the performance.
"The first was in a quiet passage of the first piece," he said.
"About a dozen protesters in the choir seats stood up with a banner saying Free Palestine and started chanting and singing to the tune of Beethoven's Ode to Joy.
"They were drowned out by the orchestra as the passage of music got louder and were ushered out."
Theartsdesk.com music reviewer Igor Toronyi-Lalic, who was at the show, said: "The whole hall was groaning and trying to slow clap them out.
"It had the atmosphere of a riot."
There had been increased security measures for the concert, including bag searches and a heightened police presence.
Police confirmed there had been no arrests but there were heated exchanges between not only supporters of both political sides but also concert-goers angry at the disruption to their evening.
Anti-Israel protesters have targeted classical music performances before.
In August 2008, five members of the Scottish Palestine Solidarity Campaign disrupted a concert by the Jerusalem String Quartet at Edinburgh's Queen's Hall.
The BBC said it would broadcast part of the concert on 7 September at 14:30 BST.