The mosque attended by the American Muslim mass murderer Omar Mateen has been damaged in an arson attack.

Mateen murdered 49 people and wounded 53 the worst mass shooting in US history at the gay Pulse nightclub in Orlando, Florida in June. He was himself killed in a police shootout.

Flames were seen rising from the mosque and police called, according to Major David Thompson of St Lucie County Sheriff's office.

The attack occurred at the start of the Islamic holiday of Eid ul-Adha.

 Thompson said the attacker was caught on security cameras: "Immediately after the individual approached, a flash occurred and the individual fled the area." 

Mateen himself was initially reported to have been a patron of the club and to have used gay dating websites, but the FBI has said it has not substantiated these claims. According to the CIA, no links have been found between Mateena and Islamic State.

The US Muslim Moner Mohammad Abu Salha, who drove suicide bomb truck into a restaurant in Ariha, Syria in 2014 killing several members of the Syrian armed forces at the same time, attended the same mosque.

There have been several incidents around the mosque targeting Muslims since the shooting.

Additional reporting by Reuters.