Hundreds of people marching for Aboriginal rights have disrupted official Australia Day celebrations in the Melbourne CBD.

The group – holding Aboriginal flags and chanting "always was, always will be Aboriginal land" – followed the parade down Swanston Street, flanked by police.

The rally came after more than 100 special interest, sporting and cultural groups had marched from the Melbourne Town Hall to Kings Domain as part of the Australia Day Parade.

Thousands of spectators watched the parade, which began with a flag raising ceremony at town hall attended by Victorian Governor Alex Chernov, Premier Daniel Andrews and Opposition Leader Matthew Guy.