Thousands of Iranians have demonstrated in defiance of a final warning by the head of the Islamic Revolutionary Guards Corps (IRGC) that he would bring protests to an end with unprecedented force. Rallies were held on the streets on Sunday to protest against raids on student dormitories over the weekend in which students were taken away in buses to state detention. Some were sent text messages saying they were banned from campus indefinitely. Some of the crowds appeared to be the largest since the protests began more than five weeks ago over the death of the 22-year-old Kurdish woman Mahsa Amini while in police custody. Amini had been arrested by the “morality police” for allegedly breaching the Islamic republic’s strict dress code for women. Maj Gen Hossein Salami, the IRGC’s commander-in-chief, had warned on Saturday that that would be the last day of “riots”. The largest gathering was at the central Tehran branch of Islamic Azad University, but other protests occurred on the university’s North Tehran campus. Security forces responded by using teargas and firing pellet guns. Students at Qazvin International University chanted the slogan: “From Zahedan to Shiraz, I sacrifice my life for Iran.” At Mazandaran University, the crowds chanted: “If we do not stand together, we are killed one by one.” At some universities, students had dismantled partition walls in canteens put there to separate men and women. Restrictions on media access made it hard to judge the breadth of the protests, but they appeared larger and more defiant than ever. Supporters of the regime insisted only a small minority were protesting, but acknowledged they have continued far longer than they expected. The IRGC and the Basij, a paramilitary police force, were true to their word on Saturday, entering a number of campuses in an attempt to arrest students that they had on their lists, sometimes as many as 100. The security forces were also seeking the cooperation of authorities to lock the gates of universities and only let out those not listed for arrest. As part of the crackdown, authorities arrested the protest rapper Tomaj Salehi, releasing a photo of him blindfolded in the back of a car. They claimed he had been arrested as he tried to leave the country, a claim challenged by his family, who said he had been captured at his home in Bakhtiari province. The prosecutor accused him of “propaganda activity against the system”. The new surge in protests has been prompted by emotional 40th-day commemorations of demonstrators killed in the initial wave of rallies, leaving Iran locked in a cycle of violence and dissent. In a bid to quell protests, the IRGC buried the body of Reza Haghighatnejad, a well-known exiled journalist, away from his home town, fearing demonstrations if they allowed the family to go ahead with the burial. He had died in Berlin from cancer aged 45 and his relatives had had his body flown home. However, authorities seized the body at Shiraz airport and refused to hand it over to his family. Haghighatnejad’s sister posted on her Instagram account a photograph of the purported burial site outside the city of Shiraz. “One person … only one person should come and tell me where in history such cruelty has been inflicted to a sister,” she wrote. More than 300 journalists have put their names to a letter demanding the release of two journalists who were among the first to report on the death of Amini. In their joint statement, they warned that “without free and responsible journalism, the society will not be able to identify and solve its problems”. Niloofar Hamedi took a photo of Amini’s parents hugging each other in a Tehran hospital where their daughter was lying in a coma. Elaheh Mohammadi sent a vivid dispatch from the highly emotional funeral for Amini in her Kurdish home town of Saqqez. Both have been detained for more than 35 days. Mehdi Rahmanian, the director of the Sharq newspaper where Hamedi works, issued a statement saying Hamedi’s reporting had been responsible and conducted in cooperation with him. He said she had not been the first to Amini’s death. Her husband denied that she had taken the photo of Amini in a coma on the hospital bed. In an ominous statement on Friday, the IRGC intelligence department claimed Hamedi had been trained abroad by western intelligence agencies, a claim that was rejected. The scale of the protests has left the regime veering from threats to promises of dialogue about why young people feel socially excluded. The head of the Revolutionary Guards in the Khorasan Junubl province, Brig Gen Mohammadreza Mahdavi, was quoted by the state news agency Irna saying: “So far, Basijis have shown restraint and they have been patient.” “But it will get out of our control if the situation continues.”