Two men were being held in custody in Northern Ireland on Tuesday after being arrested over the attempted murder of a police officer.
The men, aged 34 and 25, were arrested on Monday in the Belfast area, said a spokeswoman for the Police Service of Northern Ireland (PSNI).
The targeted officer found the viable device underneath his car in east Belfast on Sunday. Army bomb disposal experts carried out a controlled explosion.
A group calling itself the “New IRA” (Irish Republican Army) claimed responsibility for the attack.
“Detectives investigating the attempted murder of a police officer on the Upper Newtownards Road in east Belfast on Sunday have arrested two males aged 25 and 34,” a PSNI spokeswoman said.
“These arrests were made in the Belfast area.
“There are no further details at this time.”
Senior officers have said the attack could have killed the off-duty policeman and his family.
The attack has been blamed on dissident republicans who want Northern Ireland to leave the United Kingdom and join the Republic of Ireland to the south, but have not given up violence as a means to achieving their aims.
The IRA declared a formal end to its armed campaign in 2005, saying that it would pursue its aims through peaceful means.
Its political wing Sinn Fein is now part of the Northern Irish executive.
Around 3,500 people died in Northern Ireland’s three decades of violence between Protestants, favouring continued union with Britain, and Catholics seeking a unified Ireland.
A 1998 peace agreement largely ended the conflict, but sporadic unrest and bomb threats continue as dissident offshoots remain violently opposed to the power-sharing government in Belfast, formed of Catholic and Protestant parties.
Protestant Loyalists rioted in Belfast last month over a decision by the city’s council not to fly the British flag all year round.