A councillor has described a nail bomb attack on an east Belfast home as "a foolhardy and reckless act that might have caused serious injury".
A woman was uninjured but left shaken after the device partially exploded.
The DUP's Adam Newton said the attack on Bloomfield Road had been the latest in a series in the area.
"These dreadful acts are condemned by the vast majority of residents who want only to live in peace and quiet," he said.
"Those who skulk around under cover of darkness with their faces covered carrying out such acts have nothing positive to offer the people of east Belfast."
Police said they received a report that a firework had been thrown at the property at around 11.45pm on Friday.
Detective Sergeant Rory McPhillips said: "When officers arrived at the scene we discovered that it was in fact a crudely-made improvised explosive device packed with nails.
"It had been thrown at the house, along with a number of fireworks.
"The device had partially exploded, scattering nails and shrapnel across the garden. A woman who was in the house at the time was not injured.
"Nearby residents were not evacuated, but were asked to stay at the rear of their properties until Ammunition Technical Officers made the device safe."
Mr McPhillips appealed for witnesses to phone the PSNI on 101, quoting reference number 1633 of 18/5/18.
"We would particularly like to hear from anyone who saw two males riding mountain bikes in the area around the time of the incident," he added.
"We believe they may have information that could help our investigation.
"They are described as being on dark-coloured bikes and wearing dark clothes with their hoods up and faces covered.
"They may also have been wearing workmen's gloves. They were seen riding off towards the Grand Parade area."