Police have received reports that suggest explosive devices may have been thrown at Sinn Féin offices in west Belfast and left outside SDLP offices in north Belfast.
PSNI Chief Inspector Peter Brannigan police are “seeking to establish the veracity” of the information regarding premises on the Falls Road.
“The local community is asked to be vigilant and report anything out of the ordinary to police,” he added.
Sinn Féin MP Paul Maskey has condemned those responsible for the alerts, which he described as “very concerning”.
“I condemn those responsible - they have nothing to offer society and they bring nothing but disruption to the local area,” he said.
“This is an attack on the entire community and an attempt to undermine democracy, but it will not succeed.
“Sinn Féin will not be deterred by these types of incidents and will continue to serve the entire community.”
SDLP deputy leader Nichola Mallon has said that her party will also not be intimidated or deterred.
“Earlier today, the PSNI contacted my office in north Belfast following a report that an explosive device had been left outside,” she said.
“I want to make it clear that neither I nor my party will be intimidated or deterred by those responsible.
“We are committed to representing people in north Belfast and in every community across Northern Ireland.”