The head of the radical far-right Lehava organization, Bentzi Gopstein, was arrested Thursday evening after members of his group gatecrashed and disrupted a performance by a church choir at the Clal Center mall in Jerusalem.

Lehava opposes intermarriage and the assimilation of Jews and tries to stifle any public activity by non-Jews in Jerusalem and around Israel. Another member of the group was also arrested, Haaretz newspaper said.

“Two right-wing activists were arrested after they refused to obey police orders, and continued to interfere with the event and disrupted public order with shouts and confrontations with police,” Haaretz quoted the police as saying.

Gopstein and his activists burst into the event, which was the finale of the capital’s Manofim festival of contemporary art, claiming it was a Christian event and confronting those present.

According to Haaretz, the protesters began shouting during the performance by the choir of Jerusalem’s Armenian Church, reportedly yelling “Jew murderers!” and “Go back to Syria.” The disruption also forced the choir to end their performance after just one song.

A Lehava protester carries a sign reading, 'Get out, unclean ones,' at a protest decrying a YMCA Christmas bazaar in Jerusalem on Sunday, November 29, 2015 (Times of Israel)

A Lehava protester carries a sign reading, ‘Get out, unclean ones,’ at a protest decrying a YMCA Christmas bazaar in Jerusalem on Sunday, November 29, 2015 (Times of Israel)

Gopstein also confronted police who arrived at the scene to restore order. Army Radio quoted Lehava activists who witnessed Gopstein’s arrest as saying that he was struck by a Border Police officer and needed medical care.

Security forces were subsequently stationed at the entrance to the event and prevented Lehava members from going in, Haaretz said.

Lehava head Bentzi Gopstein seen during an Interior Affairs committee meeting in the Israeli parliament on November 10, 2015. (Yonatan Sindel/FLASH90)

Lehava head Bentzi Gopstein seen during an Interior Affairs committee meeting in the Israeli parliament on November 10, 2015. (Yonatan Sindel/FLASH90)

Wadie Abunassar, the executive director of the Assembly of Catholic Bishops in the Holy Land, condemned what he called the “barbaric” disruption by Lehava activists and demanded firm legal action against the group.

“We strongly condemn this barbaric act and call on the Israeli law enforcement authorities to put Gopstein and his people on trial, not only for this incident, but for all their activities that are full of violence and incitement,” Abunassar said in a written statement issued Friday.

“We take this opportunity to mention that we filed a police complaint against Gopstein over a year ago for similar actions,” he added. “Likewise, we condemn any justification to infringe on the freedom of expression of any person.”

Dov Lieber contributed to this report