Swift action from the Israelis in response to the killing of a group of young soldiers.
Police have shot dead a Palestinian truck driver who rammed a group of soldiers in Jerusalem, killing four and injuring 17 others.
Prime Minister Benjamin Netanyahu says they know who he was and he's likely a supporter of Islamic State.
He says troops have sealed off the neighbourhood where he lived and are are carrying out what he's calling "other actions".
He won't say what that involves - but a government source says ministers are calling for the demolition of the attacker's home.
They also don't want his body returned to his family for burial.
All of those killed were in their 20s.