A bomb detonated outside the City of Culture office in Derry, police said tonight.
There were no reports of injuries and police have yet to reveal details on the extent of the damage caused.
It is the second time that the office has been targeted after a pipe bomb planted by dissident republicans in January caused minor damage to the building.
Derry’s winning of the UK City of Culture title has secured cross-community support in the North.
The city’s Shipquay Street was closed off tonight by officers investigating the blast which they reported at around 11pm.