The Defense Ministry suspended single-day work permits for Palestinians to enter Israel Sunday, hours after a Palestinian teen injured four in a stabbing attack on Tel Aviv’s beachfront.

The attacker, identified as an 18-year-old from the Nablus area of the West Bank, apparently entered Israel with one such pass, as part of a group known as “Natural Peace Tours,” which is supposed to forge relationships between Palestinians and Israelis, a defense official said. He was not named.

The ministry’s Coordinator of Government Activities in the Territories said the one-day permits granted to different organizations and groups will be “frozen” until an investigation of the matter can be conducted, the official said.

Four people were hospitalized with light injuries after the attacker, who has not been named, went on a stabbing spree in the Leonardo Beach hotel on Tel Aviv’s Hayarkon Street, near the city’s famous beach, on Sunday afternoon.

He was apprehended by police, but has not yet been charged. After initially saying the motivation of the attack was unclear, police later determined that it appeared to be a terror attack.

Magen David Adom paramedics arrive at the scene of a suspected terror attack outside of a Tel Aviv hotel on April 23, 2017. (courtesy)

Magen David Adom paramedics arrive at the scene of a suspected terror attack outside of a Tel Aviv hotel on April 23, 2017. (courtesy)

The victims were identified as a man in his 70s, as well as two men and a woman in their 50s.

Israel gives out some 100,000 work permits to Palestinian to work in Israel. Holders of work permits and their relatives are heavily vetted by the Shin Bet security service for any links to terror organizations.

In addition, one-day permits are occasionally given out for special cases, such as tourism or for NGOs to hold meetings. A COGAT spokesperson said “many” of those types of permits were normally given out, but could not give an exact number.

Officials say tens of thousands more Palestinians are in Israel illegally, most of them for work.

Palestinian workers wait to cross through a checkpoint in Bethlehem, June 2, 2013 (Neal Badache/FLASH90)

Palestinian workers wait to cross through a checkpoint in Bethlehem, June 2, 2013 (Neal Badache/FLASH90)

While in the past Israeli defense officials have frozen work permits wholesale in response to terror attacks, former Defense Minister Moshe Ya’alon maintained a stated policy during a terror wave a year ago of keeping work permits in place in order to avoid collective punishment and lower tensions.

Though a marked drop has been recorded by security officials in recent months, 41 Israelis, two Americans, a Briton, a Palestinian and an Eritrean national have been killed in the spate of stabbing, car-ramming and shooting attacks that began a year and a half ago.

Israeli officials have said that many of the attackers have done so due to personal problems, with some, like Friday’s attacker, hoping to commit suicide by cop or soldier.

According to AFP figures, some 250 Palestinians, a Jordanian and a Sudanese migrant have also been killed, most of them in the course of carrying out attacks, Israel says, and many of the others in clashes with troops in the West Bank and at the Gaza border, as well as in Israeli airstrikes in the Gaza Strip in response to rocket attacks.

The spate of Palestinian attacks that began in October 2015 was dubbed the “lone wolf” intifada, as many of the attacks were carried out by individuals who were not connected to any terror group.