Five Soviet-made rockets were fired at France's most advanced nuclear power station Monday night, causing little damage but marking a new phase in the campaign against atomic power.

The attackers used Soviet-made RPG7 antitank rockets fired from a hill 600 yards away across the Rhone River at Creys-Malville, scoring four direct hits on the nuclear plant's concrete outer shell, police said.

There was no danger of radioactive leaks because the reactor was unloaded and there were no radioactive materials on the site, plant officials said.

No one was injured in the attack.

An anonymous caller claimed responsibility in the name of a "Pacifist and Ecologist Committee" in a telephone call to a French news agency, the police added.

The Creys-Malville site has been the scene of fierce nuclear opposition in the past. A West German demonstrator died at the site in 1977 during fighting between antinuclear forces and police.

The 1,200-megawatt reactor, still under construction and due to join the French nuclear grid in 1983, has provoked determined opposition because its new fast-breeder core will produce plutonium.

Ecologist and conservationist movements denounced the attack but said they remained resolute in opposing the ambitious French nuclear program, third largest in the world.