RANGELEY — Searchers examining sonar imagery on Friday believe they have spotted two snowmobiles and possibly a third at the bottom of Rangeley Lake.

Another day passed with three missing snowmobilers still unaccounted for. The Maine Warden Service reported that open water that was present early this week on Rangeley Lake has now frozen over.

With warmer weather in the forecast, wardens said recovery efforts will be evaluated next week. In the meantime, searchers plan to continue monitoring the area with aircraft.

Side-scan sonar imagery technology used on Thursday revealed a pair of snowmobiles at the bottom of the lake and searchers believe a third image may also be one of machines used by one of the missing riders.

The three snowmobilers — Kenneth Henderson, 40, of China, Glenn Henderson, 43, of Sabattus, and John Spencer, 41, of Litchfield — have been missing since New Year’s Eve.

Officials said the trio left Carrabassett Valley for a ride at 6 p.m. Sunday and have not been seen since. The men are presumed dead.

A vigil for the three men was held Wednesday night at Oxford Plains Raceway, where the three were race car drivers.

The Warden Service Friday night again cautioned that, although frozen, Rangeley Lake remains very dangerous and travel on the lake should be avoided.