Baghdad (AFP) - Iraqi security forces Friday opened fire on dozens of protesters gathering in Baghdad for a fourth day of demonstrations against corruption, unemployment and poor public services, an AFP correspondent reported.

The security forces fired directly at the protesters, not in the air, the correspondent said. There was no immediate word on any casualties.

In escalating protests since Tuesday, thousands of demonstrators have clashed with riot police and troops in the capital and cities across the south, leaving more than 30 people dead, two of them police officers.

Tensions have been exacerbated by a near-total internet blackout as the authorities seek to prevent protesters communicating with each other or posting footage of the chaotic demonstrations.

The demonstrations are the biggest challenge yet to Prime Minister Adel Abdel Mahdi, who has imposed curfews in Baghdad and other cities to try to stop the protests gathering steam.

In his first public address since the protests began, the embattled premier made a televised speech early Friday as heavy gunfire rang out across Baghdad.

He said the turmoil could lead to "the destruction of the state, the entire state", but refrained from directly responding to the protesters' demands.

Instead he defended his government's record over its first year in office and pledged a monthly stipend for families in need, while asking for time to implement a reform agenda promised last year.

Other leaders have been more supportive of the protesters, with President Barham Saleh urging the security forces to respect their right to peacefully demonstrate.