Avitan arrived in Malaysia from the United Arab Emirates on March 12 on a French passport, police said. He was detained by police at a Kuala Lumpur hotel with a bag containing the weapons.
The 17-year-old suspect suffered minor wounds and was arrested. No police were injured during the arrest.
The cell planned to attack Ben-Gvir in Kiryat Arba using rocket-propelled grenades and other weapons.
The shooting took place at the Viertola school in Vantaa, a suburb of the capital Helsinki, which has around 800 pupils from first to ninth grade and a staff of 90 people.
Security forces found documents, media, phones, and other evidence indicating Haniyeh's involvement in serious security offenses.
The man was also caught in possession of six guns and 200 bullets.
Gershkovich, his paper, and the US government all strongly deny the charges against him, which carry a sentence of up to 20 years in jail.
A man in his 40s has been detained in relation to the crime, after related content was found on his devices.
Soldiers who were operating at the checkpoint stopped the vehicle and, after searching it, found the explosive device on the side of the car door.
The minister was speaking at an event held by her party, the ruling African National Congress (ANC), on the subject of the Israeli-Palestinian conflict.