Terrorists from the Gaza-based Army of Islam are believed to have participated in Sunday’s cross-border attack in Sinai and Israel, Egyptian officials told Al-Hayat, a London-based Arabic newspaper on Tuesday.

The terrorists behind the well-planned attack, which took the lives of 16 Egyptian soldiers, were believed to have worn explosive belts and managed to commandeer an armored truck containing 1,000 pounds of explosives.

They smashed into the Kerem Shalom border crossing and drove more than one kilometer into Israel before the Israel Air Force blew up their vehicle.

Army of Islam, a US-designated terror group also known by its Arabic name Jaysh al-Islam, is linked to al-Qaeda and the kidnappings of Israeli soldier Gilad Shalit and Alan Johnston, a BBC reporter. It had previously been closely associated with Hamas.

Two days before the attack, the Shin Bet intelligence service warned the army of a potential attack by a terror cell — allegedly comprised of Bedouin and other gunmen from the Sinai Peninsula — with close links to and the possible participation of Gaza-based terrorists.

Israel and Egypt have yet to formally declare who they believe is behind the attack.

A spokesman for Hamas leader Ismail Haniyeh condemned the attack and denied his group’s involvement.

Hamas, which has controlled Gaza since 2007, sealed off the smuggling tunnels between Sinai and Gaza in the aftermath of the attack. Egypt also shut down the Rafah crossing, Gaza’s only gateway to Egypt, following the incident.