NOTRE-DAME-DES-LANDES, France (Reuters) - French police fired teargas and stun grenades and were pelted with stones during a dawn swoop to clear eco-activists and anarchists from a site in western France that had been planned as a new airport.

The site in Notre-Dame-des-Landes had been squatted for years by opponents of the plan to build a 580-million-euro ($710 million) airport which the government decided to drop in January.

Some 2,500 police took part in the evacuation which authorities said started at 6 a.m. (12 a.m. ET). Police had already blocked surrounding roads as early at 3:30 a.m., a Reuters journalist saw, while protesters set fire to barricades.

One police officer sustained an eye injury and a protester was arrested, said a police official who described the clashes as sporadic and relatively minor.

Ministers said the squatters had been ordered to leave after they had succeeded in getting the airport project halted. “We want to put an end to a lawless zone,” the Interior Ministry said in a statement.

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“Illegal constructions must be brought down for things to come back to normal in Notre-Dame-des-Landes,” Interior Minister Gerard Collomb told Europe 1 radio.

Plans for a “Great West” trans-Atlantic gateway to France and Europe were first considered in the 1960s and the Notre-Dame-des-Landes site was identified in 1967, but the project stalled until being revived in 2000.

Supporters of the airport plan, designed to handle 4 million passengers a year initially, said it would have helped economic development in the Loire-Atlantique region. An old, inner-city airport 30 km (20 miles) to the south was congested and a security risk, they said.

But opponents said it was too costly, environmentally damaging and that there was another underutilized airport 110 km (70 miles) to the north, near Rennes in Brittany.

Construction giant Vinci has said it is ready to discuss government compensation for the loss of its contract to develop Notre-Dame-des-Landes.