Israeli police have arrested four Jewish men suspected of being among gun-waving extremists filmed celebrating the murder of a Palestinian toddler in a firebombing.
They were shown in a wedding video, broadcast last week by an Israeli news channel.
It spread online and even drew strong condemnation from Israeli politicians including Prime Minister Binyamin Netanyahu.
"Four people have been arrested until now," police spokesman Micky Rosenfeld told AFP.
"An investigation was opened last week and, during this week, four people were arrested and are scheduled to appear tomorrow morning in front of a Jerusalem court" for a remand hearing, he said.
"That's in connection with the weapons that were at the wedding and other things."
He gave no further details, but Israeli public radio said among those arrested were the groom, a soldier who lent his assault rifle to another reveller and a former activist of the outlawed Kach extremist movement allegedly shown brandishing a weapon and calling for revenge against Arabs.
The video showed guests dancing with guns, knives and at least one unlit Molotov cocktail, while slashing a picture of the toddler killed in the firebombing of his home that also fatally wounded his parents and was blamed on Israeli "price tag" activists.
Local media reported that the groom had previously been questioned over acts of "Jewish terrorism" while other guests were friends or relatives of suspects arrested over the July attack.
|A Star of David and the words 'revenge' and 'long live the Messiah' were spray-painted on a wall near the family's small house during the attack|
Netanyahu called the video "shocking" and said it showed "the true face of a group that constitutes a danger to Israeli society and to the security of Israel".
In recent weeks, Israel has arrested a number of suspected extremists over the 31 July incident in the West Bank village of Duma. So far, no one has been charged.
One of them, an 18-year-old settler, was put under house arrest on Tuesday after weeks in the custody of the Shin Bet domestic security service, media reported.
He was ordered released on Monday, when prosecutors admitted that they did not intend to charge him over the Duma killings, but over a 2013 assault on a Palestinian.
The fire killed 18-month-old Ali Saad Dawabsha, while his parents later died from severe burns. Ali's four-year-old brother was the sole survivor from the immediate family.
A Star of David and the words "revenge" and "long live the Messiah" were spray-painted on a wall near the family's small house during the attack.