Iraqi security forces fired on anti-government protesters in the main northern city of Mosul on Friday, killing at least one of them, activists said.

"Fire from police and the army in Al-Ahrar Square resulted in the killing of a protester," spokesman for the demonstrators Ghazi al-Faisal said, identifying the dead man as Mahmud Saleh Yassin.

Hamad Salman, the head of the coordinating committees for the protests in Nineveh province, of which Mosul is the capital, also reported deadly fire against the demonstrators.

A police officer told AFP that protesters began throwing stones at security forces after Sheikh Hussein al-Obaid al-Juburi, a supporter of the demonstrations, was arrested at the square on Friday on terrorism charges.

A policeman fired in the air in an effort to disperse them, and when they continued throwing stones, other police opened fire, the officer said.

Protesters have taken to the streets in Sunni-majority areas for more than two months, calling for the resignation of Prime Minister Nuri al-Maliki and decrying the alleged targeting of their minority community by the Shiite-led authorities.