A man who caused panic at a Baltimore theatre by shouting "Heil Hitler!" and "Heil Trump!" during a showing of Fiddler on the Roof has apologised, explaining the outburst was his ill-conceived attempt to protest President Donald Trump's immigration policies.

"I was trying to compare Trump to Hitler because he plays into the fears of the people, and, and, and it just came out wrong," Anthony Derlunas II told WBAL-TV from his front porch, where several reporters tracked him down on Friday – two days after police removed him from his balcony seat at the Hippodrome Theatre.

"I realise now that it was so hurtful in how it came out antisemitic," Mr Derlunas said in a shaky voice. "I have no hate in me."

Mr Derlunas told the Baltimore Sun he drank several glasses of wine before the musical, which tells the story of a Jewish family persecuted for their faith in imperial tsarist Russia and opened at the Hippodrome two weeks after a gunman killed 11 people at a Pittsburgh synagogue.

"That didn't help my thinking one bit," Mr Derlunas said.

The 58-year-old said the act's final scene – in which an antisemitic pogrom disrupts a Jewish wedding – reminded him of Mr Trump's immigration policies, which call for mass deportations and a wall along the US southern border.

So during the intermission, with the wine still infusing his logic, Mr Derlunas stood up from his seat in the balcony to make a performance of his own.

"I meant to put it in that light of a dictatorship and no compassion and mercy," he told WJZ.

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What happened instead became the subject of a brief police investigation and viral videos. Mr Derlunas allegedly shouted, "Heil Hitler!" and "Heil Trump!" and made a Nazi salute from the balcony as people jumped from their seats and ran for the exits – some expecting another massacre to follow the shouts.

"The next thing I expected to hear was gunshots, frankly," said Rich Scherr, who filmed the commotion from below as Mr Derlunas's balcony neighbours appeared to confront him.

Mr Derlunas said he realised his error immediately. "Instantly it was like, 'Oh my God, what did you do?'" he told the Sun.

Security personnel escorted him and his girlfriend out of the theatre. At least one frightened patron had called 911 and an officer arrived at the lobby shortly before 10pm to interview Mr Derlunas.

"It appeared to this officer based on my interview of Mr Derlunas that his intention was to express his dislike of Donald Trump," the officer wrote in his report. He had no criminal history and so was released from Hippodrome – with lifetime ban from returning.

"I would ban me too if I was in their position," Mr Derlunas told the Sun on Friday, after the Anti-Defamation League demanded his prosecution for what the group called an "antisemitic outburst."

In his doorstep interviews, Mr Derlunas tried to convince any sceptics that espousing bigotry had been the opposite of his intent.

"The thing that I can't stand is Trump spreading hatred, and what did I do? I spread hatred," he told the Sun.

"I'm torn apart, I can't eat, I can't sleep," he told WJZ. "I'm so disgusted and upset with myself for doing what I did."

He has been trying to make amends. Mr Derlunas's listed phone number was not accepting incoming calls over the weekend. The Sun reported he had phoned the theatre and the Baltimore Jewish Council to apologise and was trying to reach local rabbis to do the same.