A group of far-right protesters holding American flags disrupted an event featuring London Mayor Sadiq Khan on Saturday, attempting to conduct a “citizen’s arrest” of the mayor after he dissed U.S. President Donald Trump. Khan’s speech on gender equality at the Fabian Society was delayed by several minutes as police ushered the demonstrators out of the building, according to multiple reports. The protesters, believed to be members of the White Pendragons group, accused Khan of “subverting the English constitution” and demanded he be arrested. They were escorted out by police after several minutes of their “non-violent” protest. The incident appeared to stem from Khan’s remarks on Trump’s planned visit to London, which he said was canceled because the American president feared widespread protests. After the protesters were ousted on Saturday, Khan took another jab at Trump. “It is a pleasure to be here even though we were distracted by the actions of what some would call very stable geniuses,” he said.