Three men have died on Mount Fuji in the first two days since the summer climbing season fully started for Japan's highest peak.

All three were found on the Shizuoka Prefecture side, where three trails opened on Wednesday. The other trail on the Yamanashi Prefecture side has been available since July 1.

A man in his 60s was found unconscious near the seventh station just after 4:30 a.m. on Thursday. He was later confirmed dead.

Earlier on Wednesday, police were alerted around 2 p.m. that a man was lying unconscious near the peak. The man in his 70s reportedly appeared to have fallen 5 meters into the crater. He was also confirmed dead.

Police say his body had injuries believed to be from the fall. When the police were notified, it was windy and rainy near the peak.

Police are trying to identify the two climbers, while looking into the cause of their deaths.

In a separate incident, another man was found collapsed near the eighth station of a trail after 5 p.m. on Wednesday.

The man showed no signs of life, and was confirmed dead on Thursday afternoon. Police identified him as a 77-year-old from a Tokyo suburb.

Police say the three men were apparently all solo climbers.

Police are warning hikers not to take risks when going up the mountain as the weather can change quickly.