CAIRO/WASHINGTON, Oct 2 (Reuters) - Islamic State has claimed responsibility for a shooting that killed at least 50 people and wounded over 400 in Las Vegas early on Monday, however, U.S. officials said that there was no evidence the shooter was linked to the group.

An FBI special agent said on Monday that there was "no connection" between the shooter and an international terrorist group.

One U.S. official said there was reason to believe that the shooter, whom police identified as 64-year-old Stephen Paddock, had a history of psychological problems.

Islamic State issued a statement through its Amaq news agency claiming responsibility for the shooting, saying that the attacker had converted to Islam a few months ago.

"The Las Vegas attack was carried out by a soldier of the Islamic State and he carried it out in response to calls to target states of the coalition," the group's news agency Amaq said in reference to the U.S.-led coalition fighting the group in the Middle East.

39 PHOTOS Route 91 Harvest country music festival shooting in Las Vegas See Gallery Route 91 Harvest country music festival shooting in Las Vegas LAS VEGAS, NV - OCTOBER 02: A cowboy hat lays in the street after shots were fired near a country music festival on October 1, 2017 in Las Vegas, Nevada. A gunman has opened fire on a music festival in Las Vegas, leaving at least 20 people dead and more than 100 injured. Police have confirmed that one suspect has been shot. The investigation is ongoing. (Photo by David Becker/Getty Images) LAS VEGAS, NV - OCTOBER 01: ( A person lies on the ground covered with blood at the Route 91 Harvest country music festival after apparent gun fire was heard on October 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino. (Photo by David Becker/Getty Images) LAS VEGAS, NV - OCTOBER 01 People run from the Route 91 Harvest country music festival after apparent gun fire was heard on October 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino. (Photo by David Becker/Getty Images) LAS VEGAS, NV - OCTOBER 01: A person lies on the ground at the Route 91 Harvest country music festival after apparent gun fire was heard on October 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino. (Photo by David Becker/Getty Images) LAS VEGAS, NV - OCTOBER 01: People dive for cover at Route 91 Harvest country music festival after apparent gun fire was heard on October 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino. (Photo by David Becker/Getty Images) LAS VEGAS, NV - OCTOBER 01: People tend to the wounded outside the festival ground after an apparent shooting on October 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino. (Photo by David Becker/Getty Images) LAS VEGAS, NV - OCTOBER 01: People run from the Route 91 Harvest country music festival after apparent gun fire was hear on October 1, 2017 in Las Vegas, Nevada. A gunman has opened fire on a music festival in Las Vegas, leaving at least 20 people dead and more than 100 injured. Police have confirmed that one suspect has been shot. The investigation is ongoing. (Photo by David Becker/Getty Images) LAS VEGAS, NV - OCTOBER 01: People take cover at the Route 91 Harvest country music festival after apparent gun fire was heard on October 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino. (Photo by David Becker/Getty Images) LAS VEGAS, NV - OCTOBER 01: A person runs from the Route 91 Harvest country music festival after apparent gun fire was heard on October 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino. (Photo by David Becker/Getty Images) LAS VEGAS, NV - OCTOBER 01: People scramble for shelter at the Route 91 Harvest country music festival after apparent gun fire was heard on October 1, 2017 in Las Vegas, Nevada. A gunman has opened fire on a music festival in Las Vegas, leaving at least 20 people dead and more than 100 injured. Police have confirmed that one suspect has been shot. The investigation is ongoing. (Photo by David Becker/Getty Images) LAS VEGAS, NV - OCTOBER 01: A man in a wheelchair is taken away from the Route 91 Harvest country music festival after apparent gun fire was heard on October 1, 2017 in Las Vegas, Nevada. There are reports of an active shooter around the Mandalay Bay Resort and Casino. (Photo by David Becker/Getty Images) LAS VEGAS, NV - OCTOBER 02: Las Vegas Metropolitan Police officers run down Tropicana Ave. near Las Vegas Boulevard after a mass shooting at a country music festival nearby on October 2, 2017 in Las Vegas, Nevada. A gunman has opened fire on a music festival in Las Vegas, killing over 20 people. Police have confirmed that one suspect has been shot dead. The investigation is ongoing. (Photo by Ethan Miller/Getty Images) LAS VEGAS, NV - OCTOBER 01: A man lays on top of a woman as others flee the Route 91 Harvest country music festival grounds after a active shooter was reported on October 1, 2017 in Las Vegas, Nevada. A gunman has opened fire on a music festival in Las Vegas, leaving at least 2 people dead. Police have confirmed that one suspect has been shot. The investigation is ongoing. (Photo by David Becker/Getty Images) LAS VEGAS, NV - OCTOBER 02: People hug and cry outside the Thomas & Mack Center after a mass shooting at the Route 91 Harvest country music festival on October 2, 2017 in Las Vegas, Nevada. A gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, opened fire from the Mandalay Bay Resort and Casino on the music festival, leaving at least 50 people dead and hundreds injured. Police have confirmed that one suspect has been shot. The investigation is ongoing. (Photo by Ethan Miller/Getty Images) LAS VEGAS, NV - OCTOBER 02: UNLV student Ajay Narang (L) and a Las Vegas Metropolitan Police Department officer use Narang's skateboard to help deliver bottled water to people at the Thomas & Mack Center after a mass shooting at a country music festival on October 2, 2017 in Las Vegas, Nevada. People who could not go to hotel-casinos that were closed after the shooting are temporarily staying at the center. A gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, opened fire from the Mandalay Bay Resort and Casino on the music festival, leaving at least 50 people dead and hundreds injured. Police have confirmed that one suspect has been shot. The investigation is ongoing. (Photo by Ethan Miller/Getty Images) LAS VEGAS, NV - OCTOBER 02: A Las Vegas Metropolitan Police Department officer helps deliver blankets and food to people at the Thomas & Mack Center after a mass shooting at a country music festival on October 2, 2017 in Las Vegas, Nevada. People who could not go to hotel-casinos that were closed after the shooting are temporarily staying at the center. A gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, opened fire from the Mandalay Bay Resort and Casino on the music festival, leaving at least 50 people dead and hundreds injured. Police have confirmed that one suspect has been shot. The investigation is ongoing. (Photo by Ethan Miller/Getty Images) LAS VEGAS, NV - OCTOBER 02: People are directed to rides outside the Thomas & Mack Center after a mass shooting at a country music festival on October 2, 2017 in Las Vegas, Nevada. People who could not go to hotel-casinos that were closed after the shooting are temporarily staying at the center. The gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, opened fire from the Mandalay Bay Resort and Casino on the music festival, leaving at least 50 people dead and hundreds injured. Police have confirmed that one suspect has been shot. The investigation is ongoing. (Photo by Ethan Miller/Getty Images) LAS VEGAS, NV - OCTOBER 02: Concert-goers wait for a ride outside the Thomas & Mack Center after a mass shooting at a country music festival on October 2, 2017 in Las Vegas, Nevada. People who could not go to hotel-casinos that were closed after the shooting temporarily stayed at the center. The gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, opened fire from the Mandalay Bay Resort and Casino on the music festival, leaving at least 50 people dead and hundreds injured. Police have confirmed that one suspect has been shot. The investigation is ongoing. (Photo by Ethan Miller/Getty Images) LAS VEGAS, NV - OCTOBER 02: A Las Vegas Metropolitan Police Department officer helps deliver bottled water to people at the Thomas & Mack Center after a mass shooting at a country music festival on October 2, 2017 in Las Vegas, Nevada. People who could not go to hotel-casinos that were closed after the shooting are temporarily staying at the center and residents are donating supplies. The gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, opened fire from the Mandalay Bay Resort and Casino on the music festival, leaving at least 50 people dead and hundreds injured. Police have confirmed that one suspect has been shot. The investigation is ongoing. (Photo by Ethan Miller/Getty Images) LAS VEGAS, NV - OCTOBER 02: Concert-goers wait for a ride outside the Thomas & Mack Center after a mass shooting at a country music festival on October 2, 2017 in Las Vegas, Nevada. People who could not go to hotel-casinos that were closed after the shooting temporarily stayed at the center. The gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, opened fire from the Mandalay Bay Resort and Casino on the music festival, leaving at least 50 people dead and hundreds injured. Police have confirmed that one suspect has been shot. The investigation is ongoing. (Photo by Ethan Miller/Getty Images) LAS VEGAS, NV - OCTOBER 02: A Las Vegas Metropolitan Police Department officer helps deliver bottled water to people at the Thomas & Mack Center after a mass shooting at a country music festival on October 2, 2017 in Las Vegas, Nevada. People who could not go to hotel-casinos that were closed after the shooting are temporarily staying at the center and residents are donating supplies. The gunman, identified as Stephen Paddock, 64, of Mesquite, Nevada, opened fire from the Mandalay Bay Resort and Casino on the music festival, leaving at least 50 people dead and hundreds injured. Police have confirmed that one suspect has been shot. The investigation is ongoing. (Photo by Ethan Miller/Getty Images) A pair of cowboy boots is shown in the street outside the concert venue after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. October 1, 2017. REUTERS/Las Vegas Sun/Steve Marcus LAS VEGAS, NV - OCTOBER 02: Police officers stop a man who drove down Tropicana Ave. near Las Vegas Boulevard and Tropicana Ave, which had been closed after a mass shooting at a country music festival that left at least 2 people dead nearby on October 2, 2017 in Las Vegas, Nevada. The man was released. (Photo by Ethan Miller/Getty Images) Metro Police officers pass by the front of the Tropicana hotel-casino after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. October 1, 2017. REUTERS/Las Vegas Sun/Steve Marcus LAS VEGAS, NV - OCTOBER 02: A Las Vegas Metropolitan Police officer stands in the intersection of Las Vegas Boulevard and Tropicana Ave. after a mass shooting at a country music festival nearby on October 2, 2017 in Las Vegas, Nevada. A gunman has opened fire on a music festival in Las Vegas, killing over 20 people. Police have confirmed that one suspect has been shot dead. The investigation is ongoing. (Photo by Ethan Miller/Getty Images) Las Vegas Metro Police officers work near the concert venue after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. October 1, 2017. REUTERS/Las Vegas Sun/Steve Marcus A body is covered with a sheet in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. October 1, 2017. REUTERS/Las Vegas Sun/Steve Marcus Las Vegas Metro Police and medical workers stage in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. October 1, 2017. REUTERS/Las Vegas Sun/Steve Marcus TPX IMAGES OF THE DAY An ambulance leaves the concert venue after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. October 1, 2017. REUTERS/Las Vegas Sun/Steve Marcus An ambulance heads to a hospital after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. October 1, 2017. REUTERS/Las Vegas Sun/Steve Marcus Medical workers stage in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. early October 2, 2017. REUTERS/Las Vegas Sun/Steve Marcus Las Vegas Metro Police officers gather near the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. early October 2, 2017. REUTERS/Las Vegas Sun/Steve Marcus Las Vegas Metro Police officers confer near a staging area in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. early October 2, 2017. REUTERS/Las Vegas Sun/Steve Marcus Las Vegas Metro Police and medical workers stage in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. October 1, 2017. REUTERS/Las Vegas Sun/Steve Marcus Las Vegas Metro Police officer stands by at a staging area in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. early October 2, 2017. REUTERS/Las Vegas Sun/Steve Marcus Las Vegas Metro Police and medical workers stage in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. October 1, 2017. REUTERS/Las Vegas Sun/Steve Marcus Police form a perimeter around the road leading to the Mandalay Hotel (background) after a gunman killed at least 50 people and wounded more than 200 others when he opened fire on a country music concert in Las Vegas, Nevada on October 2, 2017. Police said the gunman, a 64-year-old local resident named as Stephen Paddock, had been killed after a SWAT team responded to reports of multiple gunfire from the 32nd floor of the Mandalay Bay, a hotel-casino next to the concert venue. / AFP PHOTO / Mark RALSTON (Photo credit should read MARK RALSTON/AFP/Getty Images) Metro Police officers speak with a man near the concert site on October 2, 2017, after a mass shooting during a music festival on the Las Vegas Strip in Las Vegas, Nevada, U.S. REUTERS/Las Vegas Sun/Steve Marcus Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

(Reporting by Mark Hosenball; Editing by Chizu Nomiyama and Jeffrey Benkoe)

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