Activists from Greenpeace scaled the cross on Mount Royal Tuesday morning to unfurl a banner protesting the clear-cutting of forests.

About six people dressed in orange jumpsuits climbed up the tower at daybreak, while three more stood on the ground holding small signs.

The large banner read "Defender of the forests: Justice".

Dozens of police officers and firefighters were on the ground surrounding the cross, equipped with ladders if needed to bring people down.

In a TV interview a representative of the environmental activist group said those who were climbing risked being arrested, but said that was a small price to pay for bringing attention to the dangers of cutting down forests.

The six men and women were arrested around 11:30 a.m. when they descended from the cross.

Police said the group, aged 19 to 28 years old, should be charged with mischief.

In November three Greenpeace activists climbed into the Biosphere on Ile Ste. Helene to unveil a banner calling for Russia to release 30 people who were arrested in September 2013 for protesting at an oil rig.

Meanwhile this morning, 60 Greenpeace activists climbed onto the exterior of France's oldest nuclear power plant and hung a banner reading "Stop risking Europe."

France gets most of its electricity from nuclear power, while other European countries rely on coal.