18-year-old woman shot dead and sister injured in Derry
An 18-year-old woman has been shot dead and her sister has been seriously wounded in County Londonderry.
The shootings happened at a residence in William Court, Bellaghy, shortly after 10:00 BST on Saturday.
Just over an hour later, police arrested a 26-year-old man on suspicion of murder.
They also detained a man and a woman, both aged 28, on suspicion of helping an offender. All three were arrested in the Toome area of County Antrim.
The Deputy First Minister of Northern Ireland, Martin McGuinness, described the shooting as "truly shocking" and said expressed his sympathy to the victims' family.
Mr McGuinness, who is the MP for Mid Ulster, said: "People I have spoken to in the area this morning are in a state of shock.
"I would wish to extend my thoughts and prayers to the family and friends of the victim at this terrible time."
Ulster Unionist MLA for the area, Sandra Overend, said it was a "terrible tragedy".
She lives just outside Bellaghy village and told the BBC she has been inundated by concerned local residents since news of the shooting broke.
The MLA condemned the use of a gun in the incident.