Israel Police arrested three residents of an Arab village in the north on Friday, on suspicion of starting a fire in the area of Alon Hagalil, a community in the Lower Galilee.
The arrests bring the number of suspects in custody to 15.
Prime Minister Benjamin Netanyahu has vowed to treat those who are behind part of the wave of fires as “terrorists.” The detainees were all held on suspicion of setting or inciting at least some of the hundreds of fires that have engulfed Israeli towns and forests this week.
The families of the three suspects said they started a peaceful bonfire in the village grounds and remained close to it until it was doused, and as such there was no basis to the allegations against them, the Ynet news website reported.
Nazareth Magistrate Court extended their remand until Monday.
Earlier Friday, a 24-year old man was arrested on suspicion of inciting people to deliberately start fires, police said. He was to appear Friday in court in the southern city of Beersheba.
The suspect, a Bedouin from southern Israel who allegedly posted messages on Facebook urging arson, was the first to be detained for incitement. Arab MKs called for his release, saying his post was sarcastic and was misunderstood. Seen by The Times of Israel, the post concludes with a hashtag “Sarcasm, not serious.”
Ynet identified him as the son of a prominent leader of the Islamic Movement and said his Facebook post had said “there are still forests where the fire has not reached, we need our crazy youths to do what is needed.” The report did not name him.
Police also arrested another person Friday on suspicion of starting the blaze that destroyed at least 10 homes in the village of Beit Meir in the Jerusalem hills overnight. He was taken in for questioning, police said.
“We believe there are arsonists out there, but also weather conditions that allow this to spark [without human aid],” Jerusalem police chief Yoram Halevy told Army Radio after the first arrest.
The 15 detainees also include six people who the Shin Bet security service and police believe are responsible for starting some of the devastating fires that ripped through Haifa on Thursday, causing the evacuation of 75,000 people and damage to hundreds of homes.
Officials said Friday morning that 600 homes had been damaged in Haifa, some 37 of them totally destroyed, and that some fires were still burning, but there were no longer any major conflagrations in the city.
In recent days, many Arabic-speaking social media users in Israel and abroad have cheered on the fires, causing the Arabic-language hashtag label “Israel is burning” to reach the third-most trending tag on Twitter in several nearby Arab countries.
But Israeli security officials warned against jumping to conclusions about the cause of the wave of fires, saying the evidence for a widespread campaign of arson remains ambiguous.
Also Friday, MK Yael German from the Yesh Atid party appealed to Attorney General Avichai Mandelblit to take action against Rabbi Shmuel Eliyahu of Safed after he reportedly issued a religious ruling allowing people to shoot Arabs caught setting fires.
“Act immediately to end this racism and incitement,” she wrote.
Judah Ari Gross and Dov Lieber contributed to this report