MONTREAL - More than two-thousand people marched in Montreal yesterday to call for a moratorium on shale gas development.

The protesters were joined by a group who arrived in the city after a month-long walk along the St-Lawrence River.

During the 700-kilometre trek, the group stopped in dozens of small towns rich in gas reserves to spread its message.

Philippe Duhamel, who led the walk, is calling for a 20-year moratorium on shale gas development.

He says the process used to unlock natural gas from shale contaminates groundwater and wrecks the environment.

The Quebec government has slowed development of its shale-gas deposits due to public concerns about the environmental consequences.