MEDICINE HAT, Alta. - Convoys of trucks rolled slowly through Alberta and Saskatchewan on Saturday as demonstrations in support of Canada's ailing oil and gas sector continue.

Police in Medicine Hat, Alta., estimate that 650 vehicles took part in a convoy that began on the Trans-Canada Highway east of the city and continued west to weigh scales before turning around and dispersing.

A similar event in Estevan, Sask., brought around 450 trucks, according to a police estimate.

Truck convoys began last weekend in Alberta. One event on Wednesday brought more than a thousand vehicles to Nisku, south of Edmonton.

Jerry Sabine, an organizer of the convoy in Medicine Hat, says trucks were driving slowly to show people "the frustration of how slow the oilfields are."

Saskatchewan Premier Scott Moe tweeted his support for the event in Estevan, saying people across Western Canada are fed up with what he called the Trudeau government's indifference toward the energy sector.