There’s no evidence to suggest that the man who allegedly ambushed a Philadelphia police officer last weekend was part of a larger terrorist group or that he planned for more attacks, FBI Director James Comey said Thursday.

The announcement came after Philadelphia police received a tip from a citizen on the street who said that the alleged gunman, Edward Archer, was part of a larger group that posed an ongoing threat to police.

Speaking to reporters on Thursday, Comey said that the FBI will continue to investigate the Jan. 7 shooting of police officer Jesse Hartnett as a terrorist attack, according to the Associated Press. After apprehending Archer, police say he told them that he had carried out the attack in the name of Islam and pledged allegiance to the Islamic State.

Archer was charged with attempted murder but hasn’t entered a plea and is being held without bail.

[Philadelphia police, FBI investigating if alleged shooter was part of radical group]

Hartnett, the police officer, survived the attack and remains in the hospital. He will require multiple surgeries to treat his injuries, the AP reported.

Edward Archer. (Philadelphia Police Department via AP)

According to Philadelphia police, Archer, 30, opened fire on Hartnett’s cruiser as it drove down a Philadelphia street last week. He was carrying a stolen gun. Hartnett, though injured, fired back, hitting Archer in the buttocks and preventing him from fleeing.

“This guy tried to execute the police officer,” Police Commissioner Richard Ross Jr. said at a news conference last week. “The police officer had no idea he was coming.”

Comey told reporters Thursday that investigators are continuing to understand Archer’s motive and determine whether anyone else was involved.

He added that “for many months now” the Islamic State has been trying “to motivate people to kill police officers and military service members,” according to the AP.

The FBI is investigating the recent shooting of a Philadelphia police officer. "So far, we see no indication that he was part of an organized cell of any sort and no indication that there is any follow on plot connected to that," said FBI Director James Comey. (Reuters)

Local and federal officials are still investigating how strong a connection, if any, Archer may have had to outside terrorist groups. An FBI spokesperson told The Washington Post last week that the agency is looking into trips Archer took to Saudi Arabia and Egypt in 2011 and 2012.

Archer’s mother, Valerie Holliday, told the Philadelphia Inquirer that her son was a devout Muslim who had suffered head injuries and had been “acting kind of strange lately.”

“He’s been talking to himself,” she said. “He’s been hearing voices in his head. We asked him to get medical help.”

Comey declined to comment on Archer’s mental state, the AP reported.