State Duma Deputy Dmitry Gudkov has sent a letter to Interior Minister Vladimir Kolokoltsev, asking that an investigation be opened into an attack on PARNAS opposition party leader Mikhail Kasyanov, the RBC news website reported Thursday.

In the letter, Gudkov requested that the identity of the attackers be determined and said that the incident should be given “special consideration due to possible further politically-motivated attacks.”

“Despite the lack of any real injury to Kasyanov, I think that the aforementioned incident should be seriously investigated, because the attack came after constant anonymous threats on his life,” Gudkov wrote in his letter, RBC reported.

He also noted that the murder of opposition leader Boris Nemtsov in 2015 was preceded by similar threats that were not investigated thoroughly.

The attack on Kasyanov happened on Tuesday in the La Bottega Siciliana restaurant in central Moscow. Kasyanov was approached by two men “of Chechen appearance” who threw a cake at him and called him “the enemy.”

Another attempt to attack the politician was carried out on Thursday, when Kasyanov visited the city of Vladimir, the Meduza news site reported.

Activists from the People’s Liberation Front nationalist movement picketed the venue where Kasyanov was supposed to give a press conference and threw eggs at the politician when he arrived, but missed the target.

Duma Deputy Gudkov Requests Investigation Into Kasyanov Attack