SANAA – Rocks and batons flew in central Sanaa on Monday as pro-democracy protesters clashed violently with police and supporters of President Ali Abdullah Saleh, witnesses said.

Clashes between police and protesters also erupted in the city of Taez, south of Sanaa, where thousands of people joined demonstrations against Saleh, witnesses said.

In Sanaa, around 3,000 protesters marched from Sanaa University towards Al-Tahrir square in the city centre demanding that Saleh -- in power for 32 years -- step down, an AFP reporter said.

Streets echoed to chants of "After Mubarak, Ali," referring to the ouster of Egypt's Hosni Mubarak who quit after 18 days of protests by hundreds of thousands of Egyptians centred on Cairo's main square, also named Tahrir.

There were shouts of "No corruption after today" as some demonstrators brandished banners reading: "The people want to oust the regime" -- slogans used by protesters in Egypt.

As the protesters approached the square, baton-wielding riot police moved in and clashes broke out, witnesses said.

Despite razor wire erected by security forces around the square, Saleh supporters who have been camped at the square for days to thwart anti-regime demonstrations waded in to the demonstrators with batons, witnesses said.

The protesters responded by hurling stones at them, and witnesses said some demonstrators were slightly injured.

A BBC journalist, Abdullah Ghorab, his face covered with blood, told AFP he was beaten "by men from the ruling party."

The BBC said it would protest to Yemeni authorities about the "deliberate assault" on Ghorab and his cameraman.

"The BBC condemns this assault on our journalists who are trying their best in very difficult circumstances to report on the situation in Yemen," said director of global news Peter Horrocks.

Some pro-Saleh activists shook portraits of their president towards the protesters.

In the Taez clashes, witnesses said at least eight demonstrators were hurt.

Sanaa has been the scene of near-daily protests since January, and last week supporters of the president took over Tahrir square where they erected tents.

Anger at rampant corruption helped to fuel the protests that led to the ousting of Tunisia's and Egypt's presidents and fed the wrath in Yemen.

On Monday, government employees in Yemen's southern city of Aden dragged their company chairman from his office after a two-day strike demanding his resignation, they told AFP.

The workers at Yemen Gulf of Aden Port Corporation stormed company offices and removed Mohamed Bin Aefan and other officials, the workers said.

"We've had it with corrupt officials and it's time to tell them to leave," said Ali Bin Yehya, an official at the company which employs around 1,500 people.

"What happened in Egypt and Tunisia motivated the workers to demand their rights."

In Sanaa, protests have becoming increasingly violent, despite Saleh -- elected to a seven-year-term in September 2006 -- urging dialogue aimed at forging a government of national unity.

The parliamentary opposition, grouped in an alliance known as the Common Forum which has previously led the protests, has suspended its participation in demonstrations after deciding to enter talks with the government.

The Common Forum said on Sunday it is "ready to sign a framework agreement this week... on (resuming) the national dialogue."

Saleh's party, the General People's Congress, on Monday welcomed the statement, saying it "welcomes the Common Forum's consent to what came in the (Saleh) initiative" over resuming talks, freezing constitutional amendments and postponing elections.

International human rights watchdogs roundly condemned what they said was security forces resorting to violence against peaceful protesters.

"We are appalled by these reports of vicious attacks on peaceful protesters by security forces," said Amnesty International?s deputy director for the Middle East and North Africa, Philip Luther.

"Yemen needs to rein in its security forces immediately and stop excessive use of force."

New York-based Human Rights Watch charged: "Without provocation, government security forces brutally beat and tasered peaceful demonstrators on the streets of Sanaa.

"Dozens of pro-government thugs... arrived and attacked the demonstrators" on Sunday using "batons, military assault rifles, and tear gas guns," its Middle East and North Africa director, Sarah Leah Whitson, said.