A policeman was injured in disturbances caused by migrants at what is known as the Hal Far ‘tent village’ on Sunday night.
The disturbance started at about 10pm and continued till 4am.
The Detention Service sought reinforcements from the police, who deployed officers from the Rapid Intervention Unit and district officers.
A police spokesman confirmed that three police cars were set on fire and another was damaged in the riots.
An officer was slightly injured.
Investigations are continuing.
Malta’s detention and reception facilities are currently under pressure, with several hundred migrants having arrived in Malta over the past few months.
Many were brought here following agreement for distribution to other countries and are being held in detention while arrangements are made.
The latest disturbance was by far the most serious of a number held in recent weeks, with a number of migrants having fought a pitched battle with the police, throwing stones and other objects and also damaging the premises.