The NYPD and FBI are helping a Pennsylvania police department track down a Big Apple resident who made threatening comments to a city in the Keystone State on the heels of a pair of mass shootings.

The comments were posted online under an NPR news article about Sunday’s two mass shootings, Bethlehem Police Chief Mark DiLuzio said in a Tuesday press release, declining to specify the threats.

“I will not indicate what exactly was posted, but enough was said in the comments to concern citizens who read the comments that they alerted the Bethlehem Police Department about them,” DiLuzio said.

An IP address linked to the computer used to post the comments led police to a New York City residence. Investigators — working alongside the NYPD and the FBI — have since identified the man believed to have made the post, according to the release.

The man behind the post goes by the username “Alex Asher,” DiLuzio confirmed to local news outlet WFMZ-TV, though the police chief noted the name is an alias. Investigators are questioning someone in connection to the posting, according to the report.

On Saturday, lone gunman Patrick Crusius, 21, opened fire at a Walmart in El Paso, Texas, using an AK-47-style assault rifle to kill 22 people and injured dozens more.

Just hours later, 24-year-old Connor Betts killed nine people and wounded more than 25 others, including his sister, when he unloaded on a busy street in Dayton, Ohio’s nightlife district.

Betts, who was armed with a legally-owned AR-15-style rifle loaded with 100 rounds of ammo, was shot and killed by police at the scene.