A group of university students who went kayaking on Lake Biwa in Shiga Prefecture all returned safely to shore late Monday, after being reported missing earlier in the evening, with three of their kayaks having capsized.

Around 6 p.m., police received a report from a passerby that a group comprising some 20 people appeared to have been still kayaking even though it was close to sundown, Kazuyuki Miyawaki, the deputy chief of the nearby Otsu-kita Police Station, said Tuesday.

When police officers arrived at the scene, it emerged that some 50 students from Biwako Seikei Sport College in the city of Otsu had been kayaking on the lake, and that about 30 failed to return to shore on time, he said.

It wasn’t until after 9 p.m. that all the missing students returned to shore on their own. After the three kayaks capsized, a few of the students had to swim back in the dark.

No one was injured.

Students described the lake, the largest freshwater lake in Japan, as having strong winds and high waves at the time.

Biwako Seikei Sport College issued a statement later on Monday to confirm the safety of all its students and apologize for the incident.

“We sincerely apologize for any worry or inconvenience this may have caused,” the statement read.