A third man has been charged with robbery after a window was shot at a house in Sunderland.
Northumbria Police launched an investigation into a feud between two groups in Sunderland and associated criminal activity after a window was shot at an address in Edgmond Court, Hollycarrside, on Monday.
Nineteen people have been arrested so far.
A man appeared at North Tyneside Magistrates Court this morning and has been bailed.
A business and eight houses have been searched in Sunderland and enquiries have been extended to Tyneside, with houses searched and arrests made in Newcastle.
Police say the investigation is likely to continue throughout the weekend.
T/Supt Sarah Pitt said: "Our pursuit of those suspected of being involved is relentless and there will be activity continuing over the weekend. We expect there will be more arrests and further disruption activity across the city.
"Patrols will continue throughout the weekend and I would urge anyone who is concerned to speak to an officer on patrol - they are there for our communities, to offer reassurance and answer their concerns."
Anyone with information about the incident on Monday or the on-going dispute should contact Northumbria Police on 101 quoting reference 511 290216.