More than 500 riot police, some firing tear gas, are clashing with protesters squatting in a wooded area of western France to oppose the building of a new airport there.

In a muddy, rainy standoff starting early Friday, protesters responded to police attempts to remove them by hurling sticks, stones and gasoline bombs. For two weeks, protesters have illegally occupied the site of the planned Notre-Dame-Des-Landes airport set to start operating in 2017.

Environmentalists and the far-left Green Party complain the airport will mean pollution; supporters insist on its economic benefits.

The issue has driven a wedge in the Socialist-led government of Prime Minister Jean-Marc Ayrault, which includes some Green Party members. Ayrault is the longtime mayor of the nearby city of Nantes and has championed the airport plan.