Police said around 3,000 people gathered outside the town hall in central Rīga, many of them with banners expressing support for Ušakovs, whose office and home were recently raided by anti-corruption officers.
Ušakovs' Harmony party, which organised the demonstration claimed a much larger attendance, from 7,000 to 8,000, though this figure appeared somewhat inflated. An LSM reporter monitoring the demo estimated the size to be between 4,500 and 6,000.
No charges have been brought against Ušakovs in connection with an ongoing major graft investigation at the Rīga municipal transport company, though as mayor of the city, opposition council members have said he should take ultimate responsibility for what happens in council-owned companies.
Police representative Andris Smočs told Latvian Radio that there were no public order incidents: "The event passed perfectly calmly and no one was arrested. There have been no conflict situations," Smočs said.