Sinn Fein have said it received a warning that a bomb had been placed at the home of party president Gerry Adams in Belfast.
It comes as Deputy First Minister Martin McGuinness took to Twitter to blame "anti-democratic dissidents" for overnight attacks on Sinn Fein councillors.
Mr Adams said: "In recent weeks there has been a concerted series of threats and attacks on the homes of Sinn Féin members.
"There can be no place for these type of actions nor will they deter Sinn Fein from working to advance the peace process and advance our political objectives.
“Sinn Fein will not be intimidated.”
Mr McGuinness is due to speak this morning following a series of attack on Sinn Fein party members and candidates.
In the most recent attack on Tuesday night two Sinn Fein councillors had their cars attacked in Derry.
The cars belonged to Sandra Duffy and Colly Kelly.
On Wednesday morning Mr McGuinness tweeted: "With overnight attacks on Sinn Fein Councillors Sandra Duffy & Colly Kelly in Derry, I have no doubt anti democratic dissidents responsible.
"Peace and Democracy are the only way forward. Ongoing concerted dissident attacks on SF elected reps & their families will fail.#unbowed."
Two males aged 17 and 23 were arrested in the area of Oakbridge Park on suspicion of criminal damage and are currently in custody assisting police with their enquiries.
Meanwhile, last night Sinn Fein's council leader in Belfast Jim McVeigh complained his car was attacked by loyalists as he entered City Hall for the monthly council meeting last night.
Mr McVeigh said his car was surrounded by a crowd of loyalist protesters who kicked the vehicle and struck it with sticks.
He said he planned to make a formal complaint to the PSNI about the matter.
"As I tried to enter the back gates of City Hall my car was surrounded by a crowd of loyalist protesters," he said.
"My car was kicked, bounced and struck with sticks.
"I was verbally abused, and several of the crowd were shouting insults about the murder today of Gerard Davison. Their behaviour was despicable.
"I intend to make a formal complaint to the police tomorrow and ask that the people responsible be investigated.
"Sinn Fein will not be intimidated by thugs, we will continue to pursue our equality agenda in Belfast City Council."
Also on Tuesday Sinn Fein candidate Mickey Brady said he will "not be deterred" by a third death threat in 24 hours.
On Monday Mr Brady was told by the PSNI a threat had been made against his life.
He was then told a second threat had been received in a phone call in the early hours of Tuesday morning.
On Tuesday morning there was a bomb threat at his family home.
On Monday the Newry and Armagh runner was informed of a threat just 24 hours after Deputy First Minister Martin McGuinness's home in Derry was attacked.
Mr McGuinness has said Monday's attack on his family home will not deflect him from "building the peace".
The Sinn Fein MLA was speaking after paint bombs were thrown at his house in Derry.
Mr McGuinness said his grandchildren were present at the time.
The attack has been condemned by Sinn Fein president Gerry Adams.
Mr McGuinness said: “This was an attack not just on me but on my family too, including my grandchildren who were in the house at the time.
“I would like to thank my neighbours for all their help and assistance in the aftermath of the attack.
“This attack on my family follows an arson attack on the car of a Sinn Féin member in Derry last week and on Sinn Féin election billboards and posters in the city.
“The people behind these attacks have nothing to offer the community and they are intent on dragging society back to the past.
“Neither I or the people I represent will allow them to do that.
“I will not be deflected from my work as a Sinn Féin representative and as Deputy First Minister of building a peaceful and prosperous future for all our people and creating a society built upon equality and inclusion.”