Congregants gathered as usual at the Fort Pierce Islamic Center for prayers on Sunday, the day after one of their members murdered 49 people and injured more than 50 more at a gay club in Orlando.

Omar Mateen, 29, is the second extremist to be tied to the small Florida mosque, which has about 200 regular attendees.

In 2014, Moner-Muhammad Abu Salha carried out a suicide bombing in Syria and is believed to be one of the first Americans to commit such an act overseas. Before joining the jihad, Salha lived in Vero Beach and attended the same Fort Pierce mosque as Mateen.

Congregants pray at the For Pierce Islamic Center in Fort Pierce, Florida on Sunday, a day after a former worshiper killed 49 at injured more than 50 at an Orlando, Florida gay nightclub

After prayers on Sunday, the men of the mosque gathered for a nightly meal. This month, Muslims around the world fast during the day as part of the holy month of Ramadan

While communal meals like this are common during Ramadan, members of the church said Omar Mateen would not attend these social events

The imam of the mosque says that Mateen, 29, attended night prayer services with his young son about four times a week

Before opening fire at Pulse nightclub Saturday night, Mateen called 911 and pledged an allegiance to ISIS and claimed solidarity with the Boston Bombers and the Florida man who became a suicide bomber for Al-Nusra Front in Syria - a group in conflict with ISIS. He's pictured above in a photo posted to Facebook

In 2014, Moner-Muhammad Abu Salha carried out a suicide bombing in Syria and is believed to be one of the first Americans to commit such an act overseas. Before traveling to Syria Salha lived in Vero Beach and attended the Fort Pierce mosque

On Saturday, Mateen followed in Salha's footsteps, killing 49 people partying at Orlando gay club Pulse, before he was shot dead by a SWAT team.

Fort Pierce Imam Syed Shafeeq Rahman refused to call either Salha or Mateen 'members' of the mosque, saying they only worshiped there.

Rahman says his mosque is not a radicalized one, and that he has spoken out against extremist groups like ISIS in the 11 years he has led the congregation.

This is a coincidence. There is no teaching given about extremism in this mosque. There is nothing coming in the sermon on the speeches.

'This is a coincidence. There is no teaching given about extremism in this mosque. There is nothing coming in the sermon or the speeches,' Rahman told WPTV on Sunday.

Once inside Pulse nightclub, Mateen was involved in three calls with a 911 dispatcher.

'During the calls he said he was doing this for the leader of ISIS, who he named, and pledged loyalty to. But he also appeared to claim solidarity with the perpetrators of the Boston Marathon bombings and solidarity with the Florida man who died as a suicideb bomber in Syria for Al-Nusra Front - a group in conflict with the so-called Islamic State', FBI Director James Comey said on Monday.

'The Boston bombers and the suicide bomber from Florida were not inspired by ISIS, which adds a little bit to the confusion about his motives', Comey concluded.

But Rahman said he is skeptical of Mateen's actual ties to the terrorist organization, and says he may have made the statement for publicity.

'The mosque did not radicalize him,' Rahman added. 'If something radicalized him, it might be the Internet.'

Rahman invited the press into the mosque on Sunday as his congregants gathered for prayers during Ramadan, the Islamic holy month.

Imam Syed Shafeeq Rahman says he's skeptical about Mateen's actual ties to ISIS. Rahman, who is a doctor by day, speaks to reporters at his mosque on Sunday

Rahman says that Mateen did not talk with the other congregants much, instead showing up last minute and leaving immediately at the end of prayers. Above, the basin where Muslims wash their feet at the church before prayers

The mosque is regularly attended by about 200 people. Above, a prayer service for the men of the mosque on Sunday

Since the attack, Rahman has had to call the local police for protection since they have received threats on their Facebook page. Above, a prayer service on Sunday

During the month of Ramadan, Muslims fast during the day and then gather for communal meals after the sun sets and before the sun rises.

Pictures from inside the mosque Sunday night show the men of the congregation seated on the floor for their evening meal, which is spread out on a plastic sheet.

Rahman says he knew Mateen since he was a young boy, when his Afghan-born parents moved to Florida from New York.

He described Mateen as energetic as a boy but quiet as an adult. While he attended night prayers about four times a week with his three-year-old son, Rahman says the gunman rarely socialized with any of the other men in the service - including his own father and brothers-in-law.

'As a grown-up he did not talk to anyone,' Rahman told the Sun-Sentinel. 'He was really quiet. He came at the last minute and did not talk to anybody. He would shake hands ... and take his son on his shoulders and leave.'

As a grown-up, he did not talk to anyone. He was really quiet. He came at the last minute and did not talk to anybody. He would shake hands...and take his son on his shoulders and leave.

Mateen's family, on the other hand, were more involved in the community.

Rahman says that Mateen's three sisters attend the mosque and regularly help clean the building. Since women and men pray in separate services, Rahman says he doesn't know the women very well, but that his wife speaks highly of them.

Since the attack, Rahman has had to call the local police for protection since they have received threats on their Facebook page. Someone else was also seen standing outside of the building wearing an offensive T-shirt, while neighbors have started a petition to close the religious center.

Rahman also said he did not know that Mateen was on the FBI watch list, but that the FBI had come to the mosque before to ask questions during other investigations and that they complied with authorities. Above, the scene inside the mosque Sunday night after the evening Ramadan feast

Above, another shot of the plastic sheet that was laid out on the floor for the evening Ramadan feast

Above, a description of a Muslim scholar hung up at the Fort Pierce Islamic Center on Sunday

In retrospect, Rahman says there were some aspects about Mateen that were suspicious, such as the fact that he had married and divorced at such a young age - something that is rare in their culture.

Mateen's first wife has claimed she was physically abused by Mateen during their brief marriage.

During interviews, Rahman also addressed the interview from Mateen's father, who said that his son had recently gotten very upset seeing two men kissing in the street.

Rahman acknowledged that homosexuality is indeed a sin in the Muslim religion, but he said that doesn't exclude gays from the faith.

'There is nothing outside the door that says you can't come in and worship God and be here and pray if you are gay,' he told the Palm Beach Post.