Gardai are investigating a number of violent incidents in Limerick city on Friday and Saturday.
A pipe bomb was thrown into a house on West Singland Road, Garryowen shortly before noon yesterday.
A number of people were in the house at the time but they escape injury when the device failed to explode.
A man, aged in his 20s, was arrested and is being held at Henry Street Garda station.
The area was sealed off for a period pending the arrival of the Army bomb disposal unit which removed the device shortly before 4pm.
In separate incidents a number of petrol bombs were thrown at houses in Walnut Court, Kennedy Park in the city on Friday night.
The houses suffered minor damage and no one was injured.
Gardai at Roxboro Road Garda station are investigating and can be contacted on 061-214340.
Meanwhile a a man has been arrested after a series of attacks on cars at a hotel in Limerick.
Eleven cars were broken into in the early hours of Saturday morning in the car park of the Maldron Hotel.
Supt Tom O’Connor from Henry Street Garda station said gardaí had recovered all the property stolen from the cars.