A stun grenade was thrown at businessman David Appel's house in north Tel Aviv Monday night, throwing the neighborhood into turmoil but causing no damage.

Residents of Snir Street heard a loud boom at 11 P.M. Monday night. When they rushed outside, they saw the grenade arcing toward Appel's house and called the police.

Appel and his wife were inside at the time, but Appel said he was asleep and heard nothing. His wife went outside, smelled smoke and promptly woke him.

Appel said he has no idea who threw the grenade, and "it could be it was a mistake." Other residents of the street have had grenades thrown at their houses, he explained, and Monday night's grenade might have been meant for one of them.

Alternatively, the culprit could have been a business rival, he admitted.

"But no one even warned me; I don't remember a phone call or anything. So I don't think they would go straight to throwing a stun grenade."

Another possibility is that this was a hate crime because he is ultra-Orthodox, he said.

But police are leaning toward a fourth option: that the grenade was thrown by certain dubious characters who had loaned Appel money and recently demanded it back.