Israeli police said on Sunday three suspects were arrested after two flares landed near Prime Minister Benjamin Netanyahu's residence in the central town of Caesarea.
"Three suspects were arrested overnight for their involvement in the incident" on Saturday evening, the police said in a statement, adding that the suspects would be interrogated jointly with the Shin Bet internal security agency.
The statement added that a court ordered a gag on publishing any details of the investigation or the suspects' identities for 30 days.
Two flares landed near Netanyahu's residence in Caesarea late Saturday in what Shin Bet called a "serious incident", although the premier was not at home at the time.
The speaker of parliament, Amir Ohana, accused anti-government protesters of being behind the incident.
"The writing was on the walls, on the streets, in incendiary messages and in demonstrations," he said, referring to regular anti-government protests that erupted in early 2023.
Former war cabinet member and opposition figure Benny Gantz wrote on X: "If the suspicions are true and activists are behind the firing of flares at the premier's residence, it should be said clearly: this is not protest, this is terrorism."
Shin Bet chief Ronen Bar said in a statement that it was "a very serious incident that is far from a legitimate protest".
He added: "We will not accept any violent activity against the symbols of the state. Each case will be treated with the utmost severity."
Deputy Prime Minister and Justice Minister Yariv Levin accused the perpetrators of "seeking to dismantle the country from within".
In the nine months leading up to the 7 October, 2023 Hamas attack, Israel saw mass protests over a divisive judicial overhaul introduced by Netanyahu's far-right government that opponents called a threat to Israeli democracy.
Although the reforms were suspended when the Gaza war broke out, protests against Netanyahu and his government have continued, alongside demonstrations calling for a deal to release hostages held in the Palestinian territory.
Israeli President Isaac Herzog condemned Saturday's incident and warned "against an increase in violence in the public sphere".
Saturday's incident follows a drone attack targeting the same residence on 19 October, which was later claimed by Hezbollah.
It came after Israel escalated its bombing of Hezbollah targets in Lebanon and later sent in ground troops to battle the Iran-backed militant group.
At the time, Netanyahu accused Hezbollah of attempting to assassinate him and his wife.