An 18-year-old man is "seriously ill" in hospital with head injuries after an assault in Lurgan, County Armagh.
It happened near the old Community Centre in the Shankill estate between 2000 BST and 2200 BST on Friday. Police have appealed for information.
Meanwhile, two men have suffered cuts, bruises and broken bones after being assaulted in Moy, County Tyrone, by up to eight people - including one girl.
The attack happened shortly after 0230 BST on Saturday.
Their assailants have been described as being aged in their late teens and early 20s.
Police in north Belfast are also investigating an alleged assault.
It is believed to have happened in Hillman Street near the junction of Cliftonville Road.
The Antrim Road was closed for a time while police investigated, but reopened on Saturday evening.