Israeli authorities on Tuesday said they have arrested a ring of Islamic militants who planned to set off a massive car bomb in Tel Aviv over the Passover Jewish holiday.

A statement by the Shin Bet security agency said Tuesday that agents and troops arrested 19 members of the violent Hamas group from the West Bank town of Qalqiliya connected with the plot, in which a potential homicide bomber drove a car laden with 220 pounds of explosive into the Tel Aviv area but did not detonate the charge.

The arrests took place in late March, but details were only cleared for publication on Tuesday, the day after the weeklong holiday ended.

The statement said the Palestinian driver was able to enter Israel unhindered because he has an Israeli Arab stepmother and holds an Israeli identity card. It said the car had Israeli license plates.

The statement said that for reasons not yet clear, the man turned around and returned to Qalqiliya , where the car later blew up through a technical malfunction. Nobody was injured.

The Israeli daily Haaretz said the attempt was ordered by Hamas renegades in the Gaza strip, unhappy with their movement's November cease-fire with Israel and its acceptance of the more moderate Fatah movement into a coalition government.

Hamas officials in Qalqiliya denied the account, and said they were not involved in any plot.

Palestinian police officials in the town said the 19 suspects weren't connected to any bombing. They said the militants were rounded up at a Hamas ceremony marking the third anniversary of the Israeli assassination of the group's founder, Sheik Ahmed Yassin.

Police said the car held less than two pounds of explosives, and said it was unlikely Hamas was connected because the bomb was so small. However, they said it remained unclear why the car was carrying explosives.