Members of the public found the bomb inside a cardboard box which had been left in a shelter in Princes Street Gardens, Edinburgh on 11 January 2018.

Council staff who responded found a black pipe, wiring and battery taped to the inside of the box. They called police who sealed off the area and a controlled explosion took place.

Had it successfully detonated, the bomb could have caused significant injuries.

Nikolaos Karvounakis, 35, previously pleaded guilty to a terrorism offence and at the High Court in Edinburgh on Wednesday he was sentenced to eight years and four months’ imprisonment. A serious crime prevention order was also granted.

The man claimed responsibility for the device on an eco-terrorism website, saying he was a member of the International Terrorist Mafia. His DNA was found on adhesive tape used to make the bomb.

Stephen McGowan, deputy crown agent for serious casework, said: “If this device had detonated, serious harm could have been done. Nikolaos Karvounakis put members of the public in danger through his reckless actions and this was wholly unacceptable.

“COPFS has a duty to keep the people of Scotland safe and we are committed to working with other agencies to ensure those committing offences under the terrorism legislation are brought to justice.”

Detective chief superintendent Stuart Houston, Police Scotland’s head of counter terrorism unit, said: “The sentencing of Nikolaos Karvounakis is the culmination of a four-year investigation. Police Scotland Counter Terrorism investigators worked with colleagues both in the UK and Europe, and the subsequent conviction and sentencing is testament to the dedication of law enforcement and partners that they were able to piece together the actions of this individual.

“His sentencing today highlights the continuous collaborative work being undertaken by Police Scotland, prosecutors and other key partners to keep our communities safe from the threat of terrorism which won’t be tolerated in civilised society. We will continue our partnership work to identify and protect anyone who feels vulnerable to being influenced into carrying out these types of offences.”