Toronto police searching for three teenage Chinese exchange students who went missing this week say it appears they did so deliberately.

The three students from Changsha City in Hunan province were part of a group of 30 students visiting on a four-week English immersion trip that began July 7, the Toronto Star reported.

The students are 13, 15 and 17, and disappeared from a group outing at a Lake Ontario beach Tuesday afternoon, Constable Wendy Drummond said.

"We're shedding some light on the fact that it had been planned -- that the three had decided not to meet back with the group," she said.

Drummond said none of the students spoke English well and none were familiar with the city. She wouldn't disclose whether any of them had relatives in the city.

Officials at the Chinese consulate in Toronto told the Star they hadn't heard from the teenagers.