EDMONTON - Protesters concerned about climate change have staged another sit-in at a federal cabinet minister's office.

Ten members of Citizens for Climate Justice spent seven hours at Labour Minister Rona Ambrose's Edmonton office, saying they wouldn't leave until the Harper government promises to deal with global warming. The sit-in ended Wednesday afternoon with nine people being charged with trespassing.

On Monday, the same group occupied the Calgary office of Environment Minister Jim Prentice and several protesters were charged with mischief.

Protest spokesman Martin Tweedale says Ambrose must pressure the Conservatives to push for a binding deal at international climate change talks in Copenhagen next month.