A man suspected of launching fireworks at gardaí on Grafton Street, Dublin at the weekend was arrested in south Dublin on Tuesday morning.
The man, who is in his 30s, is being questioned at Irishtown Garda station.
The suspect, who is alleged to have fired a rocket cannon firework at gardaí during an anti-lockdown protest on Grafton Street on Saturday, was being questioned under Section 30 of the Offences Against the State Act.
Suspects can be questioned on suspicion of explosives-related offences under the Act and it suggests gardaí are taking a very serious approach to the investigation into the incident.
Searches were carried out at properties in south Dublin on Monday and fireworks were found. Gardaí suspect those fireworks, which are illegal in the Republic, are linked to the man being questioned.
The man arrested on Tuesday is known to gardaí.
Using CCTV and social media footage, gardaí identified the suspect and his alleged accomplices shortly after the riot on Grafton Street.
Dun Laoghaire gardaí, backed up by members of the Armed Support Unit first attempted to arrest him at his home and at another location on Monday but he was not present.
The suspect is understood to have attended a previous anti-lockdown protest on Grafton Street in October during which gardaí arrested 11 people for public order offences.
He previously received a prison sentence for attempting to steal a sat nav from a Fire Brigade vehicle as officers put out a bonfire.
That same year he was ordered to make a donation to charity after appearing in court for obstructing a drugs search and causing a breach of the peace.
The firing of the rocket at lines of gardaí at the top of Grafton St on Saturday afternoon sparked a baton charge by gardaí and clashes with some protesters.
Gardaí arrested 23 people and about half of those have already appeared before the courts charged with various offences relating to their presence and/or activities at the disturbances on Saturday.
A number of gardaí were also injured during the event, including two who sustained broken ankles.
Gardaí had taken up positions at the top of Grafton St, on the southern end, in a bid to stop a planned anti lockdown protest group gaining access to St Stephen’s Green, which the protesters planned to occupy in a planned protest.
The Garda and Dublin City Council agreed to close the park, with gardaí then taking up a defence position to ensure protesters did not gain access to the park.
Gardaí were holding back two lines of protesters at the top of Grafton St when the fireworks rockets were fired at them, sparking clashes between officers and protesters.
Video and images of the fireworks being fired at gardaí show they were fired at point blank range and at head height in the direction of unarmed gardaí in regular uniforms.
