In Kurdistan's second-biggest city of Sulaimaniyah, several tents erected by protesters demanding political reforms at a central square were set alight by masked assailants, according to Nafit Qader, a spokesman for the demonstrators, who accused Kurdish security forces of being behind the attack.

"They came at around 2:30 am (2330 GMT on Saturday) at Tahrir Square, set fire to the tents, took some of the protesters and left," said Qader, who added that the attack had left no casualties.

"We are convinced that the attack was carried out by men linked to the Kurdish authorities," he said.

Brigadier General Hassan Nuri, head of security for Sulaimaniyah province, denied Kurdish security forces were responsible for the attack, and said an investigation had been opened into the incident.

The camp was set up on Friday and housed several dozen demonstrators, but no tents were left by Sunday morning, according to an AFP journalist.

Iraq has been hit by a series of protests nationwide since the beginning of February, with demonstrators railing against corruption, unemployment, and poor public services.

Rallies in Kurdistan have centred around Sulaimaniyah, where protesters have lamented the decades-long dominance in the region of two political parties, the Kurdistan Democratic Party of regional president Massud Barzani and the Patriotic Union of Kurdistan of Iraqi President Jalal Talabani.

Four demonstrators have been killed in clashes resulting from protests in Sulaimaniyah city since February 17.

Also overnight, the offices of a Kurdish independent radio station were ransacked in the town of Kalar, in Sulaimaniyah province, according to Mirwan Hama Saeed, an official with Metro, a Kurdish media watchdog.

"Unknown attackers came at night into the offices of the Dank radio station, they destroyed some of the equipment and stole some items," Saeed said.

The attack was the second such assault against Kurdish media in recent weeks. Overnight on February 20-21, unknown gunmen entered the offices of the Nalia television channel and opened fire on the station's equipment.

Nalia had been broadcasting live footage of demonstrations in Sulaimaniyah.