At least seven police officers were injured when they were attacked by mobs in west Belfast and Co Antrim early today.
In both incidents officers used CS Spray to quell the trouble during which two people were arrested.
In West Belfast at least four officers were hurt in the nationalist Andersonstown area when they were attacked while investigating reports of a number of men armed with baseball bats being gathered in South Link.
A crowd of at least 40 people - men and women - leaving local licensed premises attacked the officers. One officer was beaten to the ground and repeatedly punched and kicked.
A PSNI spokesman said he was detained in hospital for treatment for a suspected broken wrist and multiple cuts and bruises. One man was arrested and was later being questioned.
In Cushendall on the Co Antrim coast three more PSNI officers were injured when they too were attacked by a crowd of 50 as local pubs closed in the early hours. Officers were attempting to make an arrest in the village's Bridge Street when the crowd attacked them.
One officer suffered multiple cuts and bruises to the head and body as well as a suspected broken nose, said the spokesman. During the incident CS Spray was used to control the mob before officers withdrew from the area.
One man was arrested for assault and public order offences. Investigation to try to identify more of the trouble makers were continuing.