(CNN) -

Shortly before Buddhist mobs made a deadly rampage through Muslim neighborhoods near the town of Aluthgama, Sri Lanka last month, a man with cropped hair and glasses stood before expectant crowds to deliver an explosive speech.

Video footage of the rally, called following a traffic altercation between Muslim youths and a Buddhist monk in the coastal town, captures the speaker in full flight.

In a pointed reference to the security forces stationed nearby, he declares that the Sri Lankan police and army are Sinhalese, the mostly Buddhist ethnic majority that accounts for three-quarters of the island's 20 million people.

Then, his arm raised and his voice rising to a shriek, he issues an explicit threat to Muslims, using a derogatory term for the minority.

To roars of approval, he vows that if any Muslim, were to lay a hand on a Sinhalese -- let alone a monk -- that would "be the end" of all of them.

What is striking about the clip, aside from the viciousness of the rhetoric, is that the firebrand behind the microphone is dressed in the saffron robes of a Buddhist monk.

He is Galagoda Aththe Gnanasara, the Buddhist holy man who is the general secretary and public face of the Bodu Bala Sena (BBS, also known as Buddhist Power Force).

The ultra-nationalist Sinhalese Buddhist organization has emerged as a troubling presence on the Sri Lankan political landscape in recent years, and is blamed by many for inciting the deadly violence in Aluthgama.

"It was already a tricky situation," said Mohamed Hisham, a social media activist and businessman, who was raised in Dharga Town, a Muslim neighborhood near Aluthgama that bore the brunt of the violence.

"But I believe the presence (of the BBS) had a major impact. They are to be blamed for inciting what happened."

Nights of terror

What happened, according to witnesses and officials, is that shortly after the speech, Buddhist mobs marched through Muslim neighborhoods, ransacking dozens of homes and shops. Three Muslim men were killed, and sixteen seriously injured in the two nights of violence that followed, police said.

One month on from the violence, described as the worst attacks on Muslims in the country in years, 135 people have been arrested, police say.

But while Gnanasara has given a statement to police about the events of the day, he has yet to face any charges. A national police spokesman said officers were still considering whether he had played a role in inciting the violence. "We need to check whether he has provoked the men by making this speech," he said.

The facts that the BBS's chief demagogue walks free, that authorities allowed the rally to proceed, and that they failed to prevent the violence have created an impression that the group operates with impunity, said Hisham, fueling the fears of Muslims.

"The community is feeling that if they can go scot-free after causing this kind of mayhem, what lies ahead?"

For his part, Gnanasara rejected the suggestion that the BBS was in any way culpable for the violence, telling CNN at the group's Colombo headquarters that it had "no involvement" in the incidents at Aluthgama.

"On the contrary, our organization was trying to defuse the tension after a monk was assaulted by a group of Muslim youths," he said. "We continue to be blamed for the incidents and portrayed as Sinhala extremists. This is unfair and incorrect."

Gnanasara was among a group of monks that visited the Ministry of Mass Media and Information Wednesday to file a complaint about news coverage of the Aluthgama incident, alleging the reports had disrespected Buddhism, Sri Lankan media reported.

In an earlier statement on the BBS's website -- prompted by the cancellation of Gnanasara's U.S. visa in the aftermath of Aluthgama -- the group condemned the violence there, but acknowledged that BBS representatives had "delivered emotional speeches emphasizing the need to protect Sinhala Buddhists, who are actually a very small global minority."

'Saffron fascism'

Others believe concerns about the BBS are well founded.

Dayan Jayatilleke, a political scientist and former Sri Lankan diplomat, referred to the group's politics as "saffron fascism" and described it as "a wholesaler of the ideology of hate, especially Islamophobia."

While the BBS remained a fringe movement, he said, it appeared to be gaining influence among Buddhist clergy. "(The BBS) have to be taken very seriously indeed."

Paikiasothy Saravanamuttu, executive director of Sri Lanka's Centre for Policy Alternatives, believed the group, which he described as a purveyor of "classic hate speech," had become emboldened by the lack of censure over the events at Aluthgama.