Thousands of Ukrainian neo-Nazis holding burning torches have marched the streets of Mariupol in support of the construction of an illegal monument.

Up to 5000 volunteer Azov fighters held torches aloft and waved flags featuring the wolf-hook symbol as they streamed through the streets on Sunday chanting the slogan "coming after you!"

The procession, dubbed ‘March of the Brave’ by its organisers, was arranged to mark the opening of a monument to 10th century Slavic ruler, Svyatoslav, at the site where a statue of Lenin once stood, RT.com reports.

Azov fighters collected money for the creation and erection of the illegal statue after city authorities refused to approve it.

"If they [the authorities or anyone else] are willing to demolish the monument, they are welcome to try," Azov battalion commander and Ukrainian MP Andrey Beletsky told RT.com .

As a result of the statue's illegal status, Azov fighters will permanently guard it.

Biletsky established the voluntary Azov battalion in 2014.

A 2014 report by the UN High Commissioner for Human Rights blamed the organisation for numerous and grave human rights violations, including torture and the forced disappearances of dissidents.