ANKARA - Turkish President Recep Tayyip Erdogan on Tuesday declared a national day of mourning for Wednesday following a fire that broke out at a popular ski resort in northwestern Bolu province.

The death toll from the devastating fire at Turkiye's Kartalkaya ski resort in northwestern Bolu province has risen to 76.

"A one-day national mourning has been declared across the country tomorrow," Erdogan said at a press conference after a cabinet meeting, extending his condolences to the family of the victims.

"Those who caused such a disaster in any way, those who have negligence and fault will be held accountable before the law," he said.

He added that 17 of the wounded have been discharged and the treatment of the other wounded, one of whom is in intensive care, continues.

A fire at the Grand Kartal Hotel has left 51 others injured, Interior Minister Ali Yerlikaya said earlier in the day.

The fire broke out at 03:27 local time (00:27 GMT) in the 12-storey wooden hotel, which was accommodating 238 guests during the busy holiday season.

Initial investigations suggest the fire started in the fourth-floor restaurant area before spreading upwards, according to Bolu Provincial Governor Abdulaziz Aydin.

Authorities have detained four individuals following the fire, including the hotel owner.

Kartalkaya is a popular ski resort in the Koroglu mountains, some 300 km east of Istanbul.