ORLANDO (Web Desk) – The US gunman who launched the worst carnage on American soil since 9/11 at a nightclub in Orlando was radicalized by online Islamist propaganda, officials said, while expressing doubt that he was part of a global terrorist network.

The FBI (Federal Bureau of Investigations) said Mateen had been radicalized by Islamist propaganda, but found no evidence that the shooting had been coordinated from abroad. FBI chief James Comey said, “We see no indication that he was part of any kind of network”.

Agents are instead looking into the possible role of anti-gay bigotry. The FBI was “highly confident” Mateen had been “radicalized” while consuming online propaganda, Comey said, adding that he claimed allegiance to the IS leader Abu Bakr al-Baghdadi in a series of calls during the attack.

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

The militant Islamic State group claimed that Mateen was acting as “one of the soldiers of the caliphate in America”.

The lone gunman killed 49 and wounded another 53 in America’s most devastating mass shooting in Orlando last Sunday. The attack resembles November 13 suicide attacks in  Paris where a total of 130 people lost their lives.

Read More: Orlando club shooter “unstable” according to ex, but cleared by security

The slaughter raised questions about US counter-terror strategy and gun laws as Mateen was carrying a legally purchased rifle and a handgun.“We make it very easy for individuals who are troubled or disturbed or want to engage in violent acts to get very powerful weapons very quickly,” Obama said.

Relatives and acquaintances portrayed Mateen as a violent, unstable man who had beat his ex-wife and expressed homophobic views.

The UN Security Council unanimously condemned the attack. Vigils are also being arranged on a massive level to show solidarity with the victims.

The White House said Obama would travel to Orlando on Thursday to pay his respects to the victims’ families.

Read more: 50 dead, 53 injured in US gay nightclub mass shooting