Terrorist organisation the Real IRA is being blamed for the bombing of a UK City of Culture office in Derry last night.

The bomb, which exploded at around 11pm, is not thought to have injured anyone.

Police received a warning almost an hour in advance of the blast and cleared the immediate area. However, the device went off before the Army bomb squad arrived.

Republican sources have reportedly said that the Real IRA targeted the building because it symbolised Derry’s association with the UK.

IRA stands for Irish Republican Army. The group acts in favour of bringing about a united Ireland and ending British sovereignty over the country.

Derry will become Britain and Northern Ireland’s first City of Culture in 2013. Sources said the Real IRA regarded the UK City of Culture office to be a highly symbolic target.

Windows in buildings near to the blast were smashed.

It is the second time that the office has been targeted, after a pipe bomb caused significant damage to the building in January.

The Real IRA has attacked a range of targets in Derry over the past two years, including the city’s courthouse and a bank. Last year, the terror group reportedly told the Guardian newspaper that it was considering targeting banks and bankers.