Loyalists hijacked cars and threw petrol bombs during scenes of rioting in north Belfast yesterday.
Three cars and a lorry were hijacked and set on fire during disturbances in the Crumlin Road area at about 5.30pm.
Late last night at least one vehicle was still blazing in the Woodvale area off the Crumlin Road, near Ardoyne.
Heavy rain later in the evening calmed the area. However, about 50 police Land Rovers blocked the Crumlin Road. There were also disturbances on Cambrai Street and Enfield Street.
Police sealed off the Crumlin Road near Tennent Street and Brookfield Mill.
The disturbances came after the police investigation into the feud between the UVF and LVF in Belfast resulted in a series of arrests earlier in the day.
Following an intensification of the feud, Stephen Paul was shot dead last weekend in the Woodvale area of north Belfast. He was the third man to have died in connection with hostility between loyalist rivals in a month.
Six men were taken in for questioning yesterday by the PSNI who have appealed for information about the latest killing. They want to speak to witnesses who saw Mr Paul's killers screeching on to the busy Crumlin Road in a blue Vauxhall Astra following the murder last Saturday.
Police also raided 14 houses in north Belfast as the search for those connected to the three murders continues.
The six men arrested were taken to Antrim Road police station where they are being questioned.
Chief Supt Mike Little, the commander in charge of the operation, said: "Police are actively working to disrupt the activities of those we believe could be intent on increasing fear and intimidation.
"This ongoing operation will continue and any breaches of law will be dealt with robustly."
Meanwhile, police in England investigating the murder of a GAA official in 1997 have arrested a second person in as many days in Warwickshire.
A 39-year-old woman was taken in for questioning in Nuneaton about the shooting of Seán Brown (61) following the arrest of a 44-year-old man on Wednesday. Both are understood to have come from Northern Ireland. Mr Brown was abducted as he locked the gates of Bellaghy GAA club in Co Derry.
He was shot dead and his body was found alongside his burned-out car in Randalstown, Co Antrim. The LVF has been blamed for the murder. A fresh investigation, with detectives from outside services working alongside the PSNI, has been launched.