A petrol bomb was thrown on to the roof of an elderly couple's home in Killiney, Dublin, on Saturday night, according to gardai.
The couple, who live at Norwood, Killiney, heard the bottle break on the roof and alerted gardai. Four young men from the Ballybrack area were arrested shortly afterwards and released later that night. A file is to be sent to the Director of Public Prosecutions.
A Garda spokesman said there was some damage to the house.
The couple are understood to have had difficulties with a group of youths in the area.