A stun grenade was thrown at a wedding in the central city of Rehovot on Thursday night, hurting six people, including a woman who suffered moderate injuries.
The attack was thought to be linked to gangland violence. The Walla news site said crime boss Amos Lavi was the likely target of the flashbang, which is designed to scare, but usually not injure, those caught in its blast wave.
Israel Police said in a statement it opened an investigation into the “circumstance of a weapons explosion at an events hall” in the city.
Local police accompanied by bomb disposal experts were investigating the scene, the statement said.
Though police reported five people were lightly injured, the Magen David Ambulance service put the number at six, including a woman, 20, who was moderately injured by the blast wave and fragments.
The injured people were taken to the Kaplan Medical Center and the Shamir Medical Center.
Underworld violence between Israeli crime families occasionally bursts onto the street, with shootings and car bombs occurring semi-frequently.
In recent years, much of the violence has moved into the Arab community, with many of the 125 killings among Arabs last year attributed to gangland fighting.
Hours earlier, a man in Lod, 43-year-old Hussein Issawi, was shot to death in what was thought to be a dispute between criminal gangs.
On Thursday morning, Ammar Muhammad Hujayrat, 4 was killed by apparently stray gunfire while on a playground in the northern town of Bir al-Maksur.