An engineer with a history of making hoax bomb calls has surrendered before police claiming he had planted a low-intensity explosive device outside Mangalore airport on Monday, the purported confession blowing up in the face of those who had earlier speculated about the suspect’s religion.

Adithya Rao walked into the office of the Karnataka director-general of police on Wednesday and told the guards there who he was.

He was immediately taken to the local police station where he was questioned before being handed over to Mangalore police.

Earlier, home minister Basavaraj Bommai had set off wild assumptions when he appeared to hint that a particular community was behind the bomb scare and promised to “identity the anti-national forces who want to create panic by terrorising the people”.

The state BJP was more direct, attacking former chief minister H.D. Kumaraswamy after the Janata Dal Secular leader had suggested that such incidents might be even stage-managed to trigger communal strife.

“…Is there no appeasement politics by former CM @hd_kumaraswamy? Why cry for Jihadis?” the party had tweeted on Tuesday.

Bommai piped down soon after Rao was taken into custody and denied he had ever tried to link any religion with Monday’s incident.

“We never speculated about the suspect’s community or organisation,” Bommai said. “We had only said that whoever was behind the incident would be brought before justice, and we have done that.”

Rao, 36, a native of Manipal in southern Karnataka, had served time in jail for making two hoax bomb calls to Bangalore airport in the space of a week in August 2018.

He had started working at a restaurant in Mangalore just two weeks back, after being released from prison in November.

Rao “surrendered before us admitting he had planted the device (outside Mangalore airport)”, deputy commissioner of police Chethan Singh Rathore told reporters.

Police sources said Rao had a bachelor’s degree in mechanical engineering and had done an MBA too but never stuck to any job after starting out as an employee of an insurance company in Bangalore.

He had then worked as a security guard in a Manipal school before his first arrest.

The sources said he was a voracious reader of crime thrillers and law books when he was in Chikkaballapur prison, where he spent six months in detention.

The police said Rao had procured some chemicals and assembled the low-intensity explosive device that he left in a bag outside Mangalore airport on Monday. There were hints that it was not a professional job since the device did not have a trigger to explode it, remotely or otherwise. Bomb squad personnel triggered it manually in a deserted area.

Forensic experts from the police and the National Security Guard were analysing the powder-like substance, the sources said.

Home minister Bommai lauded the police for bringing the accused to book, although Rao had surrendered. “This reflects the impartiality with which our police work,” he said.

Kumaraswamy slammed Bommai for his earlier comment that appeared to assume the suspect’s religious identity. “Why are they (the BJP) silent now? They would have made a big deal if he was a Muslim,” the JDS leader told reporters.

Congress lawmaker and former minister U.T. Khader said the government had been trying to link the incident to Muslims from neighbouring Kerala.

“This government has been trying to link it to people from Kerala. The home minister should apologise for linking a religion to the incident since it’s now clear there was none,” Khader told reporters in Mangalore.

Rao’s younger brother Akshath Rao, who works in Mangalore, said the family had no connection with him since he started making hoax calls.

“I had spoken to him only once on the prison phone when our mother passed away in 2018,” Akshath, who lives with his father, told reporters.