On Thursday, one group of protesters managed to penetrate the embassy and stay inside for some 15 minutes before leaving when security forces arrived.

On Friday, police closed off the street past the embassy with concrete blocks and the protesters gathered on a nearby avenue.

The demonstration was again organised by supporters of firebrand Shiite cleric Moqtada Sadr, whose movement is not part of the current Iraqi government but still commands huge influence.

The protest came a day after an Iraqi citizen living in Sweden, Salwan Momika, 37, stomped on the Islamic holy book and set several pages alight in front of the capital's largest mosque.

Swedish police had granted him a permit in line with free speech protections, but authorities later said they had opened an investigation over "agitation".

The Koran burning, coinciding with the start of the Muslim Eid al-Adha and the end of the annual pilgrimage to Mecca in Saudi Arabia, sparked anger across the Muslim world.

"It's an insult to the Holy Koran," said 47-year-old civil servant Nafia Wali Idriss. "Freedom of expression must not clear the way for sectarianism."

Friday's protesters chose their own bugbears to trample underfoot -- photographs of Momika and the rainbow flag of the LGBTQ+ movement.

"No to homosexuality, yes to the Koran," the demonstrators chanted.

The Iraqi government has called on Sweden to extradite Momika so he can be put on trial in his home country.

The foreign ministry also summoned Swedish ambassador Jessica Svardstrom on Thursday to hear a strong protest against her government's authorisation of Momika's protest.

Sadr movement official, Hakim al-Zamili, said the calling in of the ambassador was not enough and demanded "more concrete measures".

Swedish Prime Minister Ulf Kristersson on Friday distanced himself from Momika's protest. "This is a serious security question. There's no need to insult other people," the right-wing premier said.

Momika told a Swedish newspaper late Thursday that he intended to repeat his protest in July. "Within 10 days I will burn the Iraqi flag and the Koran in front of Iraq's embassy in Stockholm," he told Expressen.