A senior Islamic Jihad fugitive, Khaled Dahdouh, was killed in a Gaza car bomb Wednesday afternoon.
The IDF had not confirmed involvement in the incident, and were checking if the cause of Dahdouh's death was a work accident.
In response to the death of Dahdouh, another senior Jihad member in Gaza, Abu Gandel, threatened to retaliate harshly against Israel.
"The Israelis will pay a heavy price for the stupid actions of their government," he said.
Islamic Jihad has been responsible for the majority of Kassam attacks on Israel since the Israeli withdrawal from the Gaza Strip this past summer.
Earlier Wednesday, IF troops operating in the village of Anza, south of Jenin in the
West Bank, shot a fugitive attempting to escape arrest.
The man suffered a gunshot wound to the leg, and after receiving initial treatment by soldiers at the site was taken to hospital in Israel.