A bomb which was defused by British Army experts in north Belfast last night had been left outside the offices of DUP MP, Nigel Dodds.
A caller to a Belfast newsroom claiming to represent the Continuity IRA, said that group were responsible.
Mr Dodds said the attack illustrated the need to maintain security levels in the North.
A police spokesperson said the area had now been re-opened to traffic and residents allowed to return to their homes.