The cyber unit of Lahav 433 of Israel Police has opened an investigation into anonymous threat letters than have been sent to several members of Knesset over the last few days.
The envelopes have been sent for examination.
Last year, the group known as "The Israeli Avengers" sent threatening letters to coalition MKs and their family members.
According to political sources, an investigation was launched at the time, but the perpetrator was not found, and recently, the Knesset has identified a renewed wave of letter-sending.