ORLANDO, Fla. (Reuters) – U.S. law enforcement officials investigated on Monday whether anyone helped the gunman who massacred 49 people at a gay nightclub in Orlando, but said they did not believe anyone connected to the shooting posed a current danger to the public.

The FBI and other agencies were poring over evidence inside and in the closed-off streets around Orlando’s Pulse nightclub, where a shooter pledging allegiance to Islamic State carried out the deadliest mass shooting in U.S. history.

The gunman, Omar Mateen, a New York-born Florida resident and U.S. citizen who was the son of Afghan immigrants, was shot and killed by police who stormed the club early Sunday morning with armored cars after a three-hour siege.

Officials said on Sunday the death toll was 50. On Monday they clarified that this included Mateen, who was killed by police.

Law enforcement officials were looking for clues as to whether anyone worked with Mateen on the attack, said Lee Bentley, U.S. Attorney for Florida’s middle district.

“There is an investigation of other persons, we are working as diligently as we can on that,” Bentley told a news conference. “If anyone else was involved in this crime, they will be prosecuted.”

Officials emphasized that they believed there had been no other attackers and that they had no evidence of a threat to the public.

Mateen, 29, called emergency services during the shooting and pledged allegiance to the leader of the militant Islamic State group, officials said. His father said on Sunday his son was not radicalized, but indicated Mateen had strong anti-gay feelings. His ex-wife described him as mentally unstable and violent toward her.

Islamic State reiterated on Monday a claim of responsibility for the attack.

“One of the Caliphate’s soldiers in America carried out a security invasion where he was able to enter a crusader gathering at a nightclub for homosexuals in Orlando,” the group said in a broadcast on its Albayan Radio

Although the group claimed responsibility, this did not necessarily mean it directed the attack: there was nothing in the claim indicating coordination between the gunman and Islamic State before the rampage.

The attack, denounced by President Barack Obama as an act of terror and hate, reignited the debate over how best to confront violent Islamist militancy, a top issue in the Nov. 8 U.S. presidential election campaign. Democratic candidate Hillary Clinton and her Republican rival Donald Trump both addressed the issue on Monday.

Trump has made it a centerpiece of his campaign to get tougher on security and has proposed a temporary ban on Muslims entering the country. He told Fox News on Monday that the United States should increase its military campaign against Islamic State militants, who hold land in Syria and Iraq, in response to the shooting.

The rampage began just after 2 a.m. on Sunday at the crowded Pulse nightclub in the heart of Orlando, about 15 miles (25 km) northeast of the Walt Disney World Resort. Orlando is one of the most popular tourist destinations in the United States, drawing some 62 million visitors a year.

Some 350 patrons were attending a Latin music event at the club and survivors described scenes of carnage and pandemonium as the shooter took hostages inside a bathroom.

WAITING FOR NEWS OF RELATIVES

Orlando Mayor Buddy Dyer said that 48 of the 49 victims had been identified and about half the families of those killed have been notified.

“I cannot imagine being one of the parents or knowing that your loved one might be among those who are deceased and waiting to find out,” Dyer told reporters.

Florida Governor Rick Scott asked Obama to declare a state of emergency over the attack, which would free up more federal resources to assist victims.

“Yesterday’s terror attack was an attack on our state and entire nation,” Scott said in a statement.

Mateen was an armed guard at a gated retirement community, and had worked for the global security firm G4S for nine years. He had cleared two company background screenings, the latest in 2013, according to G4S..

Despite Mateen’s 911 call expressing support for Islamic State, U.S. officials said on Sunday they had no conclusive evidence of any direct connection with foreign extremists.

“So far as we know at this time, his first direct contact was a pledge of bayat (loyalty) he made during the massacre,” said a U.S. counterterrorism official. “This guy appears to have been pretty screwed up without any help from anybody.”

Authorities said Mateen had been twice questioned by FBI agents in 2013 and 2014 after making comments to co-workers about supporting militant groups, but neither interview led to evidence of criminal activity

His father Mir Siddique, who saw Mateen on Saturday afternoon, said in a video posted to Facebook early Monday that he had not known of his son’s plans.

“I don’t know what happened and I didn’t know he had hatred,” Siddique said. “God himself will punish homosexuality. It is not the job for humankind.”

In an earlier interview with NBC news, the father described an incident in downtown Miami in which his son, saw two men kissing in front of his wife and child and became very angry.

Mateen’s former wife, Sitora Yusufiy, said he was emotionally and mentally disturbed, yet aspired to be a police officer.

Yusufiy told reporters near Boulder, Colorado, that she had been beaten by Mateen during outbursts of temper in which he would “express hatred towards everything”.

Mateen and his family regularly attended a Florida mosque. “Not everyone had a friendship with him. He wasn’t a people person. He was not extremely friendly but he wasn’t rude either,” said Mohammed Jameel, 54, a worshipper at the mosque.

Sunday night, federal agents combed through Mateen’s apartment in the Atlantic coast town of Fort Pierce, about 120 miles (190 km) southeast of Orlando.

HOMEGROWN ATTACKS

The attack in Orlando came six months after a married couple in California – a U.S.-born son of Pakistani immigrants and a Pakistani-born woman he married in Saudi Arabia – killed 14 people in San Bernardino in an shooting rampage inspired by Islamic State. The couple died in a shootout with police hours after that attack.

Obama was due to be briefed at the White House by his top national security officials including FBI Director James Comey at 10:30 a.m. ET

Obama said on Sunday the Orlando gunman’s motivation was still unclear. “We know enough to say this was an act of terror, an act of hate,” he told reporters. Obama also repeated his frustration over America’s lax gun laws.

The attacks underlined the inherent difficulties of providing security at open public events.

“We are determined to continue living in an open and tolerant way even if such murderous attacks plunge us into deep mourning,” said German Chancellor Angela Merkel, during a visit to China.

The most deadly attack on U.S. soil inspired by violent Islamist militancy was on Sept. 11, 2001, when al Qaeda-trained hijackers crashed jetliners into New York’s World Trade Center, the Pentagon and a field in Pennsylvania, killing some 3,000 people.

(Additional reporting by Barbara Liston Yara Bayoumy in Fort Pierce, Fla., Zachary Fagenson in Port St. Lucie, Fla., Omar Fahmy in Cairo, Michelle Martin in Berlin and Jonathan Landay, in Washington; Writing by Roberta Rampton and Scott Malone; Editing by Frances Kerry)