A threatening letter was sent Tuesday to the attorney involved in the extradition of the Abergil brothers to the US.
Police and bomb sappers arrived at the Kiryat Ono home of attorney Nissim Marom and searched both cars belonging to him and his wife for any explosive devices.
Residents in the surrounding homes were evacuated from their homes as well.
No explosives were found.
The case has been transferred to the National Serious and International Crimes Unit and a bodyguard may be assigned to Marom.
Yitzhak and Meir Abergil were arraigned on murder, money-laundering, extortion drug trafficking charges along with three others in a Los Angeles federal court on January 14, the Los Angeles Times reported.