Scores killed in protests across the Middle East (VIDEO)

Protests across the Middle East turned violent Friday, with pro-democracy activists reportedly killed in Syria and Yemen, while Iranians and Saudis rallied in support of Bahraini reformists, and Egyptians gathered to voice demands regarding their own rulers.

In Syria, anti-government protests broke out in several places. At least 17 people are said to have been killed in protests against President Bashar al-Assad and his ruling Baath Party in the southern city of Daraa, with witnesses saying ambulances were prevented from reaching the scene, the Guardian reports. However, Syrian state-run TV reported that it was in fact police officers who had been killed.

Syrian security forces fired tear gas and live ammunition as thousands of protesters gathered in Daraa despite overtures by Syria's president to end three weeks of unrest, Haaretz reports witnesses as saying.

There are also unconfirmed reports of deaths in Homs, Duma and Harasta, as protests swept the country.

In Yemen's southern city of Taiz, at least two people were reportedly killed in clashes between security forces and anti-government protesters, after President Ali Abdullah Saleh rejected a plan for him to step down proposed by Persian Gulf states.

Saleh told a crowd of supporters near the presidential palace in the capital Sanaa on Friday that a mediation offer by the Gulf Cooperation Council countries had been rejected, Bloomberg reports. Elsewhere in the capital, hundreds of thousands of demonstrators gathered to demand an immediate end to Saleh’s rule.

In Egypt, tens of thousands of activists reportedly gathered in Cairo's Tahrir Square on Friday demanding that ousted president Hosni Mubarak be prosecuted.

According to the Washington Post, the massive turnout reflected growing frustration with what activists see as the slowness of Egypt’s new military rulers to punish former figures in Mubarak’s regime for corruption and recoup their personal fortunes.

Mubarak and his family have been under house arrest at a presidential palace in the Red Sea resort of Sharm el-Sheikh since he was forced from office Feb. 11, banned fro travel and with their assets frozen.

In Iran, meantime, several hundred chanting protesters took to the streets in Tehran to denounce Bahrain's crackdown on pro-democracy demonstrators. And in Saudi Arabia, hundreds of people gathered in two eastern towns in support of the protesters in Bahrain, most of them Shiite Muslims.

Bahrain's crown prince reiterated this week that the government remained committed to political reforms but said there would be "no leniency" for those who try to "split our society into two halves," The National reported.

In Iraq, meanwhile, Iraqi security forces reportedly clashed with rock-throwing crowds at an Iranian refugee camp in Diyala province, killing dozens of them, according to Al Jazeera. Hospital officials said at least three people were killed, but Camp Ashraf residents said at least 25 people were killed and 320 wounded.