Maisy Odjick, left, and Shannon Alexander have been missing since Sept. 6.

Volunteers combed riverbanks on an Algonquin reserve near Maniwaki, Que., for clues in the disappearance of two teenage girls who haven't been seen in almost a month.

Shannon Alexander, 17, and Maisy Odjick, 16, were last seen Sept. 6 on the Kitigan Zibi Anishnabeg First Nation about 145 kilometres north of Ottawa.

Alexander's father, Brian Alexander, said he feels as though "someone ripped my heart out."

He said he thinks something bad must have happened to the two teens, as Shannon left her identification, clothes and backpack behind.

"Where would they go without any ID, or even clothing?" he asked Tuesday.

He added that Shannon had enrolled to study nursing at a trade school in Mont-Laurier this fall.

Kitigan Zibi police Cpl. Francis McDougall, said teens on the reserve sometimes leave Friday and come back Saturday or Sunday, but it's unusual for them to be missing this long without any word.

Nevertheless, he said there's no evidence to suggest the girls got into trouble.

Police said they received a tip that the girls had gone to Ottawa. Last week, police posted and handed out flyers there.

Meanwhile, members of the community planned another search of the reserve and surrounding area again on Thursday.