The list of places where Tony Blair must look over his shoulder for protesters during his endless carousel around the global lecture circuit now includes Hong Kong, after a speech on faith and globalisation was interrupted by an activist seeking to make a citizen's arrest on the former prime minister.

Tom Grundy, a Briton living in the Chinese territory, said he walked towards Blair a few minutes into the address at Hong Kong University (HKU) with the intention of apprehending him for alleged offences connected to the Iraq war.

The 29-year-old said he had registered online to attend the talk, which took place on Thursday evening local time. Although Blair makes considerable sums as a paid-for speaker, this event was a more personal engagement, marking a link between HKU and his own Tony Blair Faith Foundation. Grundy carried with him a sheaf of notes about the legal basis for the attempted arrest, covering, he said, alleged violations of the UN charter, the Nuremberg principles, and the Geneva and Hague conventions.

"I waited till he'd been speaking a minute or so before I stood up and went towards him and said, 'Mr Blair, under Hong Kong's Power 101 law – the law which allows for citizen's arrest here – I'll be arresting you for crimes against peace'," Grundy told the Guardian shortly afterwards.

"There was a gaggle of photographers just in front of him. As I tried to pass through them to him, one of the gentlemen with him prevented me from going any further."

To his surprise, Grundy said he was not bundled away by Blair's guards or campus security and eventually left after the police, who he hoped would assist in arresting Blair, failed to arrive. He was not arrested and was allowed to stay on campus.

The protester said he was himself "too flustered" to note Blair's reaction. "He gave the usual line about 'That's democracy in action'," Grundy said. "He was talking about faith and globalisation, and I made the point to him that he can't speak about religion when he's set back religious tolerance by decades."

Such protests have become an increasingly common feature of Blair's agenda since he left office. Last month, his testimony to the Leveson inquiry into the media was interrupted by an activist who shouted that the former PM should be arrested for war crimes. David Lawley-Wakelin, 49, gained entry to the room at the Royal Courts of Justice via an unguarded rear staircase.

Grundy said: "I think he's so used to it now, and that's part of the idea, to let him know that he should have to endure this wherever he goes. If he's at an event and the press are around, someone needs to remind him that he's a war criminal."