The homes of prominent Sinn Fein figures Gerry Adams and Bobby Storey have been attacked with explosive devices, the party said.
The republican party condemned the “reprehensible and cowardly” attacks in Belfast on Friday night - with former leader Mr Adams saying no-one was hurt.
Gerry Kelly, Sinn Fein’s Policing and Justice spokesman, said two devices were thrown, one of which caused damage to a car.
Significant damage was visible to a vehicle on Mr Adams’ driveway in the aftermath of the attack and a blast mark could be seen on the windscreen.
A heavy security presence was outside the home of Mr Storey, with a number of police Land Rovers and armed officers standing guard.
Mr Kelly, the north Belfast MLA, said: “These were reprehensible and cowardly attacks on the family homes of Gerry Adams and Bobby Storey.
“Grandchildren were in the driveway of Adams’ home minutes before the attack.
“I would appeal for calm. These attacks are the desperate acts of increasingly desperate and irrelevant groups.”
The Police Service of Northern Ireland said officers were “dealing with two incidents at two separate addresses in west Belfast”.
While police have not yet attributed responsibility, the attacks are likely the work of dissident republicans.
The extremist groups oppose Sinn Fein’s involvement in the peace process and are engaged in localised turf wars in republican strongholds in an effort to wrest support away from the mainstream movement.
Sinn Fein dismiss the dissidents as unrepresentative gangs with no political strategy that use the cloak of republicanism to engage in criminality.
Friday’s attacks in west Belfast came after six successive nights of dissident-orchestrated violence in the republican Bogside neighbourhood of Londonderry.
Sinn Fein leaders, including current president Mary Lou McDonald, were scathing in the criticism of the extremists behind the rioting and attacks on police in Derry.
Mr Adams led Sinn Fein from 1983 until February 2018, while Mr Storey has served as the party’s northern chairman.
Following the attacks, the leader of the Alliance party Naomi Long said the attacks “Must be condemned without equivocation”.
She said: “This week we have seen those who remain wedded to violence bring chaos and fear onto our streets, in scenes which we had all hoped we would never witness again.
“These latest attacks on the homes of Gerry Adams and Bobby Storey are a deliberate and calculated attempt to cause fear and raise tensions in our community.
“We have all worked too hard and come too far to see the peace we have enjoyed put at risk by those who offer nothing to this society but destruction.”