Two people have died as a result of collisions in east Belfast and Co Down.
The fatal crashes happened on Friday, ahead of three other serious weekend collisions.
Police have named the victim of a fatal crash in Comber on Friday as Ryan Mervyn Corken.
The 29-year-old, who was from the Comber area, died following a crash involving three vehicles shortly after 9.15am on Friday at the town’s Glen Road.
Following the arrival of emergency services, Mr Corken was pronounced dead at the scene.
“Our investigation into the circumstances surrounding the collision has just begun,” a PSNI spokesperson said.
“We would appeal to anyone who was in the area at the time or who may have relevant dash-cam or other footage available to contact officers at the Collision Investigation Unit on 101, quoting reference number 395 of 26/05/23.”
Mr Corken, who worked with Sliderobes UK in Belfast, was described as a “very popular and much loved” colleague by the company.
In a statement posted to social media, a spokesperson said: “Always so vibrant and full of life, with loads of ideas, he worked with a smile on his face and made the working day so much better for everyone around him.
“We are heartbroken at his loss. The office just won’t be the same without him.”
On Sunday evening the Ballygowan Road in Comber reopened after being closed following a separate serious crash earlier in the afternoon. Two people were taken to hospital for treatment to injuries.
Meanwhile, on Friday afternoon a 47-year-old cyclist died following a collision involving a lorry at Castlereagh Street in east Belfast.
The crash happened shortly after 3.30pm.
“Officers attended alongside colleagues from other emergency services. Sadly, the cyclist was pronounced dead at the scene,” a PSNI spokesperson said.
“A full investigation into the circumstances of the collision has commenced and we would ask anyone who witnessed the collision or who has relevant dash-cam footage to contact the Collision Investigation Unit on 101, quoting reference number 1224 of 26/05/23.”
On Sunday, a serious crash led to the Castlewellan Road in Newcastle, Co Down being closed at its junction with the Carnacavill Road, and the Tollymore Road, for several hours. Two people were taken to hospital, while the road reopened to traffic on Sunday evening.
In Co Derry, the A6 Glenshane Road at Dungiven was closed on Sunday following a two-vehicle crash, with diversions put in place for drivers travelling between Belfast and Derry.
The NI Ambulance Service said three crews arrived at the scene, and two people were taken to Derry's Altnagelvin Hospital.