FBI  Director James Comey was in Philadelphia Thursday to tell the city it is not in danger of further attacks like the one that left a Philly cop seriously wounded last week.

Regarding alleged shooter Edward Archer, Comey said there is "no indication that he was part of a cell, and no indication of a follow-on attack. I want to give people that assurance."

Comey said the anonymous tip reporting that Archer was part of a group with three other men who posed a further risk to Philly police was "false," and added that Philadelphia is not a "hotbed of radicalism."

RELATED: Donations pour in for family of Philly cop shot in 'ISIS'-related attack

But basic questions about why Archer fired 13 shots at Officer Jesse Hartnett on Jan. 7, striking him three times, persist.

In two separate press conferences Thursday, the two U.S. senators who represent Pennsylvania presented different interpretations of the incident.

"The dangers of radical Islamist terrorism are not limited to countries far away," said Sen. Patrick Toomey, a Republican. "ISIS is a local risk because of their ability to inspire terrorist attacks all around the world, and make no mistake about it, this was a terrorist attack."

Sen. Robert Casey, a Democrat who appeared just two hours later at police headquarters with Mayor Jim Kenney and Commissioner Richard Ross, referred to the shooting as a "lone wolf" attack, while Kenney stated, "The FBI has not concluded this was an act of terrorism."

RELATED: Kenney under fire from conservatives after Islam comments

Toomey said that Archer "was radicalized," but declined to go into specifics.

"Radicalization, I imagine, can occur in many different ways. I don't know how or in what circumstances this man came to these terrible ideas," he said.

Toomey said the two senators only had separate press conferences because of scheduling conflicts, not because of any disagreement over the case. Casey also said they "work together" on cases like this one and denied any rift in handling the Archer case.

"There's very few people in Washington that have tried to make this partisan," Casey said. "I have heard some Republican presidential candidates that should be more responsible in their rhetoric. That's an understatement."