Egyptian police HQ under siege

Riot police struggled to hold back protesters trying to storm the headquarters of Egypt's feared security forces today.

Tens of thousands of demonstrators calling for a "second revolution" continued to occupy Cairo's Tahrir Square, after rejecting a promise by the ruling military to transfer power to civilians by July.

A furious crowd gathered outside the heavily fortified Interior Ministry, prompting security forces to fire rubber bullets and tear gas.

As the violence entered a fifth day, the death toll climbed to 38. At least 2,000 people have been injured, mostly from gas inhalation or rubber bullets. Some protesters said live rounds had been fired but police denied this.

Doctor Shady el-Nagar told how three bodies arrived today at his field hospital with bullet wounds. He said: "We don't know if these were live ammunition or pellets - pellets can be deadly when fired from a short distance." UN human rights chief Navi Pillay called for an independent inquiry into the deaths, saying: "Images coming out of Tahrir, including the brutal beating of already subdued protesters, are deeply shocking."

Some activists claimed they had no wish to enter the interior ministry building but were trying to stop the police and army from evicting them from the square.

Protests are taking place across Egypt despite concessions yesterday by Field Marshal Hussein Tantawi, head of the military council. It had said a presidential poll might not happen until late 2012 or 2013, but Field Marshal Tantawi said this would be brought forward to before June 30. He insisted parliamentary elections would take place next week as planned. The concession was rejected by tens of thousands in Tahrir Square, who chanted "Leave! Leave!" and "The people want to topple the marshal."

In other Arab Spring developments:

Yemen's president Ali Abdullah Saleh arrived in Saudi capital Riyadh to sign a deal under which he will step down. Mr Saleh, 69, would transfer his powers to his deputy ready for an early election.

Bahraini security forces chased and beat youths hours before an independent report is expected to criticise the authorities over the crushing of protests this year, in which more than 40 died.