Protesters gather in Halifax on Monday as a G8-sponsored meeting kicks off at Pier 21. (Phonse Jessome/CBC)

A labour leader has been charged with assaulting a police officer after being arrested during a noisy anti-G8 demonstration in Halifax Monday morning.

About 40 people marched down Terminal Road to Pier 21, where development ministers from major industrial countries are set to meet.

Two officers struggled with a woman when police tried to move the demonstrators to a sidewalk to clear the road, said CBC reporter Phonse Jessome.

Laurie Stacy, a protester who was standing nearby, said the heavy-handed treatment was unnecessary.

"They had asked her just to move. We said we were moving, but they didn't give her enough time. The cop in charge grabbed her by her shoulder and started squeezing and just looked at her with pure hate," said Stacy.

"She told them, 'Let go of me.' They didn't. The next thing you know three of them were on top of her on the ground."

The arresting officer told CBC News that the protester pushed him.

Protest organizers identified the demonstrator as Toni MacAfee, an education officer with the Canadian Union of Postal Workers.

"It was unprovoked," organizer Kyle Buott said of MacAfee's arrest.

Bev Oda, Canada's minister of international co-operation, will kick off the G8 meeting Tuesday. The main issue is how to improve the health of the world's poorest mothers and children.

More than 200 people took part in a peaceful demonstration in Halifax on Sunday. There were no incidents and no one was arrested.

A protest organizer said G8 policies back free trade but not freedom for women.