Sources say a van was hijacked on the Shankill Road, a canister placed on board and the driver forced to drive it to Holy Cross Church. Police have put a 400 metre exclusion zone in place.
The driver of the vehicle was in tears inside the venue after alerting security officials to the incident and apologising to attendees for being forced to drive to the site.
Mr Coveney was giving an address as part of the Time to Build The Common Ground by the John and Pat Hume Foundation at the Houban Centre on the Crumlin Road.
After being alerted to a problem, the minister told the audience he had to leave and hoped to be back in a few minutes.
However, he was escorted from the area by armed gardaí and members of the PSNI. He is now said to be in a “secure location”.
An army team has been called to assess a device found in the back of the van.
Mr Coveney has since tweeted: “In Belfast with @Humefoundation to honour John & Pat’s legacy of peace for all communities.
"Saddened & frustrated that someone has been attacked & victimised in this way and my thoughts are with him & his family. My thanks to @PoliceServiceNI.”
His keynote speech was due to be followed by a discussion with community leaders, including Alan McBride of WAVE Trauma Centre whose wife Sharon, was killed in the Shankill bomb.
Tim Attwood, who was moderating the event, said it was “very unfortunate that the event has been cancelled and more importantly the disruption to local community".
“The message of the minister in the short time he was speaking and of the John and Pat Hume Foundation is that you can only achieve your goals through peaceful and nonviolent means,” he continued.
“Those who think they can drag us back to those dark days are very much mistaken, they are long gone and this will only renew our efforts for peace and reconciliation and our work will continue.”
PSNI officers are currently in attendance at the scene of the security alert.
Motorists are advised to avoid the area and seek alternative main routes for their journey.
Sinn Fein MLA John Finucane condemned the incident, saying: “The attack on an event involving Minister Simon Coveney at North Belfast’s Houben Centre today is disgraceful.
“Those behind the van hijacking which was left on church grounds have no place in society.
“While they try to bring back the past, we will keep working for the future.”
The SDLP’s Spring Conference is set to take place at 1pm in the Seamus Heaney HomePlace in Bellaghy, Magherafelt.
Colum Eastwood has tweeted: “Worrying situation in Belfast today at the Building Common Ground event.
"These mindless thugs won’t deter the John and Pat Hume Foundation from carrying out their work to further peace.
"The Hume Foundation is an organisation dedicated to promoting peace and reconciliation. The attack on them and on @simoncoveney this morning is an attempt to drag us back that will never, ever succeed.”