Denmark and Sweden have said they deplore the burning of the Koran but cannot prevent it under rules protecting free speech. Last week, protesters in Iraq set the Swedish embassy in Baghdad ablaze.

Tuesday's demonstration in Copenhagen by a group called "Danish Patriots" followed Koran burnings the group staged on Monday and last week in front of the Iraqi embassy. Two such incidents have taken place in Sweden over the past month.

Iraq's foreign ministry on Monday called on authorities of European Union countries to "quickly reconsider so-called freedom of expression and the right to demonstrate" in light of the Koran burnings.

Turkey on Monday said it strongly condemned what it called a "despicable attack" on the Koran and called on Denmark to take necessary measures to prevent this "hate crime" against Islam.

The Danish government has condemned the burnings as "provocative and shameful acts" but says it does not have the power to block non-violent demonstrators.

"People benefit from an extended freedom of speech when they demonstrate," University of Copenhagen law Professor Trine Baumbach told Reuters, explaining Danish laws. "It does not just include verbal expression. People can express themselves in various ways, such as through the burning of items."

(Reporting by Louise Breusch Rasmussen, editing by Terje Solsvik)