NEW YORK (CNN) -- Seven men have been arrested in connection with alleged threats made toward police officers since Saturday afternoon, when two NYPD officers were shot in the head from behind while sitting in their patrol car, New York City police said.
Police said in a statement Wednesday that they have assessed hundreds of online postings and calls to 911 and pressed the public to continue to report any suspicious activity.
"All threats against members of the NYPD are taken seriously and are investigated immediately to determine the credibility and origin of the information," the statement read.
The arrests come as an investigation is underway into Ismaaiyl Brinsley, the 28-year-old who authorities say shot Officers Wenjian Liu and Rafael Ramos in Brooklyn.
Hours earlier, Brinsley apparently posted on his Instagram account: "I'm putting wings on pigs today ... they take one of ours, let's take two of theirs." Brinsley committed suicide after shooting the officers, according to police.
One of the most recent arrests came on Wednesday after a 26-year-old allegedly posted pictures of weapons on his Facebook page along with threats to kill police officers, NYPD spokeswoman Sophia Mason said.
The man's Facebook post indicated that he wanted to kill two police officers, NYPD Detective Annette Markowski said. He was charged with making terroristic threats.
A 41-year-old also was arrested Wednesday on charges of aggravated harassment and making terroristic threats after he allegedly called into the 84th precinct -- where Liu and Ramos had been stationed -- and, requesting to speak to Ramos, asked whether the bullets had been removed from the dead officer's head so "he could kill more cops," Mason confirmed.
Also Wednesday, a man was arrested on weapons, drug and harassment charges after he was overheard threatening to kill cops while talking on his cell phone inside a bank in Queens, according to the NYPD.
That man is accused of saying, on the phone, that he was going to kill a cop, and that Brinsley should have killed white police officers, according to a criminal complaint filed in court. The complaint says that when police interviewed the suspect, he elaborated that two white officers should have been killed "if the guy really wanted to send a message."
Of the seven arrests, according to police, three stemmed from postings made on social media and two came on misdemeanor charges of false report incident, in which the suspects allegedly called into 911 -- reporting threats made by a third party that were later debunked. One arrest was made after the suspect phoned in a direct threat to 911.
In a tweet Thursday, Mayor Bill de Blasio thanked the police department and the civilian who saw something and said something: "Thank you to the NYPD officers who today arrested a man who threatened to kill cops, and to the good samaritan who provided key information."