The second grenade attack in Dublin in a week was today being linked to the knife murder of a young inmate in Mountjoy Prison.
Scores of people were evacuated from their homes in the Crumlin area late last night after a man hurled the explosive at a house on Slane Road.
The attack took place at around 11pm. No-one was injured and the house was believed to be empty at the time. Detectives are investigating whether the attack was retaliation for the killing of 24-year-old Derek Glennon in Mountjoy Prison on Monday night.
It is the third explosive attack in the capital this week. Superintendent Bart Faulkner, Crumlin Garda Station, said retaliation for the murder was one line of investigation.
"All that is part of our investigation, and until we find out exactly what the motive was and what actually happened at the scene I can't confirm that, but obviously that will be part of our investigation," the Supt said.
Residents were forced to leave their homes on Slane Road for more than an hour last night as a precaution as garda sealed off the area.
A man was seen throwing the device before fleeing in a dark coloured car. A car was found burnt out on the nearby Leighlin Road and detectives are examining it to see if it was linked to the attack.
The scene still remains sealed off as garda technical officers carry out a forensic examination.
Glennon, 24, was stabbed a number of times by a prisoner during a scuffle on Mountjoy's D-wing landing just before Monday evening's recess.
Prison officers were on the scene in seconds and the inmate was immediately rushed to the nearby Mater hospital but died a short time later. Declan O'Reilly (27) from Parnell Road, Crumlin was charged with the murder yesterday.
Glennon, from Stanaway Road in Crumlin, Dublin had been serving 10 years for manslaughter.
He escaped from custody in October 2005 while serving a five-year prison sentence and was subsequently seized and jailed for five years at Dublin Circuit Criminal Court.
While serving his sentence, Glennon had been taken to St James's Hospital by three prison officers for treatment. He was outside smoking when a man approached and pointed a gun at one of the officers to whom he was handcuffed forcing him to let Glennon go.
Glennon had initially been jailed in January 2004 after pleading guilty to the unlawful killing of Neil King at Davitt Road in December 2002 while driving a stolen car.
He knocked down the cyclist as he tried to avoid gardai. On Tuesday night a grenade was thrown at a house in the Coombe area which forced the evacuation of 100 homes. That attack was linked to a row involving the INLA and drug dealers.
And on Monday morning a pipe bomb was thrown from a car at a group of people as they made their way to work in the Mulhuddart area.