SAN FRANCISCO (AP) — Zynga Inc. is firing back at rival game maker Electronic Arts Inc. in a legal tussle that it says goes beyond who copied whose game.

While saying EA's copyright infringement lawsuit filed last month has "no merit," Zynga on Friday filed a countersuit against EA for allegedly violating antitrust laws by trying to prevent its employees from defecting to Zynga.

The countersuit "addresses actions by EA we believe to be anticompetitive and unlawful business practices, including legal threats," said Zynga's general counsel Reggie Davis in a statement.

Zynga alleges that EA's chief executive, Jon Riccitiello, threatened to sue Zynga if it did not agree to stop hiring away EA executives. In its counterclaim, Zynga repeatedly calls EA's original lawsuit "sham litigation" intended to scare employees and prevent them from departing.

EA spokesman John Reseburg responded Friday, saying the countersuit was "predictable subterfuge aimed at diverting attention from Zynga's persistent plagiarism of other artists and studios."

Last month, EA sued Zynga, saying that its new game "The Ville" infringes EA's game, "The Sims Social."

Zynga's legal response and counterclaim were filed in the U.S. District Court in San Francisco.

Zynga, which is based in San Francisco, has been stung recently by some high-level departures, including John Schappert, its chief operating officer. Schappert was hired by Zynga last year after being lured away from Redwood City, Calif.-based EA.