By Matthew Collin
There have been demonstrations in several parts of north-west Iran, with thousands of ethnic Azeris protesting at a newspaper cartoon.
The newspaper was shut down after last Monday's protests
Azeris said the cartoon, which was published earlier this month, compared them to cockroaches.
Reports from the cities of Ardebil, Naqadeh and Meshkin Shahr say Iranian security forces fired on demonstrators, killing at least five people.
Dozens of others were injured and hundreds arrested.
The cartoon was published in a state-owned newspaper.
It showed a succession of people attempting to talk to a cockroach in Persian.
Each time, the insect responded by saying, in Azeri: "What do you mean?"
Azeris are the largest ethnic minority in Iran, and the cartoon caused outrage among those who believed it suggested that all Azeris were stupid.
Thousands of people took to the streets in protest and, shortly afterwards, the newspaper was shut down and its editor arrested.
But that did not quell the anger. In the latest protests on Saturday, government buildings were targeted, and a number of banks and television stations burnt down.
What is ironic is that the man who drew the original cartoon is also an ethnic Azeri. He too has been arrested.