Two days before the country goes to the ballot, books of writings by the Shas party’s spiritual leader were burned on Sunday in an apparent act of revenge, and in another incident offensive graffiti marred the walls of a center-left party’s campaign headquarters as the Israeli elections reached fever pitch.

In the central city of Or Yehuda, several religious books edited by Rabbi Yitzchak Yosef, son of Shas’s spiritual leader Rabbi Ovadia Yosef, were put to the flames in the latest round of apparent infighting among Sephardi parties. The books were collections of letters written by the elder rabbi in response to religious inquiries posed by followers.

Shas supporters accused followers of the Koah Lehashpia party of torching the books, which were discovered burned early Sunday morning. However, the latter said in a statement that it deplored the burning and denied involvement.

The Koah Lehashpia party’s No. 1 told Haaretz that his party believes the culprit was a local man disgruntled with Shas’s behavior.

“From an investigation we have conducted, the person who did the deed is the owner of a shop in Or Yehuda whose Kashrut certificate Shas decided to revoke,” the paper quoted Aryeh Samarly said.

Police said the identity of culprit was known but he had not yet been apprehended. TV reports said the culprit was mentally disturbed.

Shas party leader Aryeh Deri went to visit the site of the blaze to protest against the offense.

Supporters of Shas and new rival faction Koah Lehashpia, led by Rabbi Amnon Yitzhak, have been at loggerheads ever since election campaigning began late last year. Last week Yitzhak accused Shas supporters of spraying teargas at him and his followers during a party event.

Also on Sunday morning, the slogan “Yigal Amir was right” was discovered daubed on the walls of the Hatnua party headquarters. Amir was convicted of the 1995 assassination of prime minister Yitzhak Rabin.

Hatnua party leader Tzipi Livni responded in a statement on her Facebook page in which she said the graffiti made it clear what the current struggle is all about.

“I didn’t vote for Rabin, but he was my prime minister,” she said. “No one will murder our democracy or our Zionist dream.”

Party officials said they intended to lodge a complaint with the police.