BBC at 11:00
A land search is under way to try to find a helicopter carrying five people which went missing over north Wales.
North Wales Police is coordinating the search in Snowdonia with the Coastguard and other agencies.
UK Coastguard duty commander Mark Rodaway said six mountain rescue teams and a dog unit were hampered by visibility of just 10ft (3m) in places.
The privately-owned helicopter vanished while over Caernarfon Bay en route to Dublin from Luton.
Radar contact with the red Twin Squirrel helicopter was lost on Wednesday afternoon and initial searches followed the intended flight plan of the aircraft over the Irish Sea.
Supt Gareth Evans of North Wales Police said "All available police, mountain rescue and other civilian resources are currently being utilised and we are grateful for the assistance and cooperation of the public as well as our MRT volunteers who are searching very difficult and challenging terrain."
Supt Evans said family members of those on board had been contacted by police, but their names have not been released.
Image caption HM Coastguard helicopters searched for the missing aircraft Mr Rodaway said: "These aircraft normally carry beacons that we can track by satellite - they're activated by salt water - we've not seen any of that and also mobile phone data has aided our inquiries in shifting inland."
Helicopter searches between north Wales and the shore of Dublin on Wednesday were scuppered by low lying cloud, which reduced visibility.
Mr Rodaway said the bad weather in Snowdonia gave him "concern" about sending Coastguard helicopters into the mountain range, but if weather conditions improved throughout the morning, they would be able to send air support to aid the search teams on the ground.