The federal government has dropped its charges against six Greenpeace activists who last month scaled the smokestack at the Hatfield's Ferry power station in Greene County to protest President Bush's energy policy.

The six still face state felony charges of rioting, burglary, criminal trespass and three other lesser offenses.

The U.S. attorney's office filed a motion to dismiss the federal charges Friday and a magistrate signed the order on Monday.

The activists had been charged with "destruction of an energy facility," the definition of which includes efforts to interrupt the function of a power plant.

U.S. Attorney Mary Beth Buchanan said she decided to withdraw the federal charges after being assured that prosecutors in Greene County will "vigorously pursue" the state case. A hearing in that case is scheduled for Aug. 2.

"In light of that, it was appropriate to let the state case proceed," she said.

She said her office filed the charges initially because she wasn't sure at the time what the Greene County district attorney's office would do. State police took the activists into custody after the June 23 climb, but hadn't yet filed the charges at the local magistrate's office when Buchanan decided to file a federal criminal complaint.

FBI agents had been monitoring the situation along with state troopers and later transported the six to the federal courthouse in handcuffs.

Under federal law, prosecutors had 30 days to take the case before a grand jury to seek an indictment.

Buchanan said she decided against that and filed the motion to dismiss. U.S. Magistrate Robert Mitchell signed the order "without prejudice," however, so prosecutors still have the option to seek an indictment.

Greenpeace was happy about the decision.

"It's always been our belief that these charges were inappropriate," said John Coequyt, the organization's energy policy specialist in Washington, D.C.

Chris Miller, a Greenpeace official in Masontown, Fayette County, said the state charges should be thrown out, too.

"We are cautiously optimistic as we move forward with the state stuff," he said. "This was a nonviolent, peaceful protest that did not interfere with the operation of the plant."

Miller said Greenpeace isn't done in Greene County. On Monday, the group will be in Masontown to offer free hair testing for traces of mercury, which Greenpeace said is produced by coal-fired power plants.

The organization has offered similar testing in Harrisburg and Philadelphia as part of a nationwide campaign.

The testing in Masontown will be held at the Italo American Citizens Club on Acton Street. A news conference is scheduled for noon.