Israeli forces arrested on Wednesday four family members of the Palestinian gunman who killed five people in a shooting attack in Bnei Brak the night before.
Military forces were operating the assailant's hometown of Ya'bad, near Jenin in the northern West Bank, as the probe into the deadly attack continues and as investigators work to determine whether 26-year-old Diaa Hamarsheh had any accomplices.
Overall, 19 people were arrested on suspicion of aiding the assailant or over membership militant groups in Bethlehem and Ramallah in the West Bank, and in Nazareth and Wadi Ara in Israel. The arrests include the assailant's brother and three of his cousins.
Security forces were mapping Hamarsheh's family home ahead of potential demolition.
Hamarsheh's father, Ahmad, told Haaretz that he was very surprised by what had happened "I didn't know something like this could happen," he said.
"Diaa worked with me in the tobacco trade and was unrelated to any political or military activity… the claim that he was a Fatah member is baseless."
He said his son did not show any intention to do anything unusual. "We had lunch yesterday and he said he was going to head to the center to bring stock," and added that if he had known of his son's plans, he would have tried to stop him. "Who would have wanted his son to do something like this and then lose him?"
- Terror in Israel: Why an ISIS shooter was wearing a ‘Punisher’ symbol
- Copycat attack after ISIS-inspired murders is Israel's worst fear come true
- Shooting attack kills Israeli cop, Bnei Brak residents, two Ukrainians
- Five shot dead near Tel Aviv in third attack in a week; Palestinian gunman killed
- Palestinians mark a tense Land Day after spate of deadly attacks in Israel
Shin Bet and police assess that Hamarsheh obtained the assault rifle used in the attack within Israel, after crossing the West Bank wall through a breach in the Baka al-Garbiyeh area.
The Shin Bet security service and police are investigating whether the assailant had any help from people in Israel in obtaining the rifle, or whether he purchased it illegally.
According to a preliminary investigation, Hamarsheh had worked in Bnei Brak and was familiar with the area.
He had been arrested by Israel in 2013 for security-related offenses and served a six-month sentence. While he was affiliated with Fatah during his time in prison, defense officials say they don't see Tuesday's attack as linked to the group or its military wing.
No group has claimed responsibility for the attack, but Hamas and Fatah's military wing both issued statements in support of the assailant.
Following the attack, security forces plan to crack down on Palestinians who are in Israel without permits, as Hamarsheh had been.
Security Minister Bar-Lev said that six Border Police reserve companies are called up to bolster security, three of them were scheduled to join ahead of Ramadan while the remaining three were recruited due to the latest series of attacks.
Prime Minister Naftali Bennett is expected to approve the recruitment of 200 Border Police officers who are nearing the end of their compulsory service, or have finished it.
Security officials said the police is planning to recruit some 500 volunteers with a license to carry weapons to bolster the force's activity.
Chief of Staff Aviv Kochavi ordered the IDF to go on a higher level of alert and prepare for different scenarios of escalation in a situation assessment attended by Defense Minister Benny Gantz and senior defense officials on Wednesday.
It was also decided in the meeting to let all combat soldiers and some soldiers who have gone through mid-level training to take their weapons home.
The IDF bolstered manpower in 14 combat battalions and is planning to also bolster its intelligence units.
Gantz ordered the IDF to assist Israel police by providing trainings and equipment, as well as by recruiting 1000 army combatants to aid police forces.
On Wednesday, Palestinians mark Land Day which typically sees large-scale protests and riots against Israel on the Gaza border, factions in the Strip announced that they would be holding the demonstrations by the coast, rather than on the Israeli border.
The move was made in order to reduce tensions and to avoid clashes on the border. The IDF is also bolstering its forces on the Gaza border and in the West Bank in preparation for Land Day.
"This is a test for the Arab community," a senior source in the Security Office said. "If they really condemn the terror attacks, we will see this play out in the coming days, which shall pass without any unusual events."
At this stage there is no intel regarding intentions for disorderly conduct, the source said.
A Palestinian gunman killed five people on Tuesday in a suburb of Tel Aviv, in the third deadly attack in Israel within days, prompting police to go on the highest level of alert since the fighting with Gaza last year