ORLANDO (Web Desk) – Although investigators have revealed many startling findings from the Orlando Pulse club shooting there are still many questions unanswered.

A new debate has been spurred by a source close to the Orlando investigations after he reportedly began discussing Orlando gunman Omar Mateen’s last Facebook post.

“You kill innocent women and children by doing us taste the Islamic state vengeance [sic],” Mateen wrote, according to the source.

“In the next few days you will see attacks from the Islamic State [ISIS] in the USA,” the post said.

Related: Police detains Orlando shooter’s wife for possible role in killings

ISIS also claimed responsibility for the attack on their official radio station “al-Bayan”.

“We begin from America, where Allah has enabled brother Omar Mateen, one of the soldiers of the Caliphate in America, to carry out a raid where he was able to infiltrate a Crusaders’ gathering at a gay night club in Orlando, Florida,” the radio report said.

“Allah enabled him to inflict heavy casualties amongst the filthy Crusaders,” the ISIS statement said. “He killed and injured over a hundred of them. This is the biggest raid to be carried in America after the raid of Manhattan 16 years ago. All praise to Allah.

Read More: Orlando shootings: A mother’s pain at not knowing if her son is alive

Besides terrorism, FBI is also looking into the aspect of hate crime. U.S. intelligence source revealed that Mateen pledged allegiance to ISIS and leader Abu Bakr al-Baghdadi in a phone call made to police during the shootings.

Another television producer Matthew associated to NEWS 13, claims that he talked to Mateen during the carnage. Matthew who was busy gathering information about the shooting received Mateen’s call.

“On the other end, I heard, ‘Do you know about the shooting?'”  Matthew Gentili said.

Before the producer prompted him, the caller interrupted and said:
“I’m the shooter. It’s me. I am the shooter,”and then caller said he did it for ISIS, before starting to speak in Arabic. A local television affirms that Mateen’s phone number is the same one that Matthew received.
Shooting survivor Patience Carter also confirmed that Mateen was continuously busy with his phone during the rampage.

Read More: Orlando shooting may have inspired US-national to detonate explosives