Ten people have been killed during violent clashes between pro- and anti-government supporters in a Cairo square, according to doctors at a makeshift clinic treating the casualties.

Dr Sayyid Hussein said the makeshift clinic, operating out of a mosque near the square, had registered 10 deaths.

The health minister earlier said six had been killed and more than 800 wounded.

Earlier, the US condemned the targeting of journalists by pro-government supporters in Egypt as ‘totally’ unacceptable and renewed its condemnation of violence against protesters.

White House spokesman Robert Gibbs also reiterated US calls for Egyptian President Hosni Mubarak to start an immediate transition of power ‘now’ but did not publicly call on the embattled Arab strongman to step down.

Egyptian Vice President Omar Suleiman responded that the country would not accept intervention in its internal affairs.

‘Intervention in our internal affairs is strange, unacceptable and we will not allow it,’ he said in an interview broadcast on state television.

It is understood that an Irish citizen was injured in an incident in Cairo last night and is receiving assistance from the Irish Embassy.

On Monday the army had emboldened protestors by endorsing their demands as legitimate and pledging not to open fire on them. But since Tuesday evening, when President Hosni Mubarak said he would not stand for re-election in September, the soldiers have largely stood by without intervening.

In the northeast of the country some 4,000 people started a march in Suez calling for Mr Mubarak to step down, while in Ismailia a crowd of 2,000 held a similar demonstration.

In Cairo, Egyptians lined several entrances to the square, holding hands in a human chain, and some are checking people as they enter.

Though protestors were fewer than in previous days, the level of public dissent remains unprecedented in the heavily policed state.

Prime Minister Ahmed Shafiq has apologised for the ongoing violence and said that those responsible would be held accountable.

But with many suspecting the government orchestrated the clashes, that is unlikely to calm tensions.

Opposition leaders have rejected the offer of talks with the government, insisting President Mubarak must stand down immediately.

There is also growing criticism of the Egyptian army for failing to halt the violence.

Meanwhile, the Egyptian army has been trying to separate opponents and supporters of President Mubarak.

The Reuters news agency reports that at one point, a tank turned its turret towards Mubarak supporters who were hurling rocks at protestors from a flyover.

The tank then advanced towards the loyalists, accompanied by soldiers on the ground who cleared them from the position.

The Egyptian government has claimed it has had no part in mobilising pro-Mubarak demonstrations.

Department urges 'extreme caution'

The Department of Foreign Affairs has advised Irish citizens in Egypt to exercise extreme caution and avoid demonstrations, as the situation in the country remains ‘volatile and unpredictable’.

Of the 400 Irish people who were in Egypt last week, 300 are expected to have returned to Ireland by tonight.

The Department says 25 others have flights booked to leave Egypt later in the week, while about 60 Irish residents plan to remain in the country.

Irish people are being evacuated on flights organised by British and Portuguese authorities.

Some commercial airlines have also increased their capacity on flights leaving Cairo.

Mobile firms forced to send texts

Egyptian authorities have forced mobile phone operators to broadcast pro-government messages amid protests engulfing the country, British-based operator Vodafone said today.

Vodafone condemned the ‘unacceptable’ situation, which comes after the government cut mobile communications in a bid to prevent demonstrators from coordinating their protests earlier in the crisis.

‘Under the emergency powers provisions of the Telecoms Act, the Egyptian authorities can instruct the mobile networks of Mobinil, Etisalat and Vodafone to send messages to the people of Egypt,’ Vodafone said in a statement.

‘Vodafone Group has protested to the authorities that the current situation regarding these messages is unacceptable. We have made clear that all messages should be transparent and clearly attributable to the originator.’

Several text messages have been sent out via mobile operators in Egypt since mass protests against the rule of President Mubarak began on 25 January.

One read: ‘The armed forces are looking after your security and will not resort to violence against this great people.’

‘To every mother, father, sister, brother, to every honourable citizen: preserve this country because the fatherland is everlasting,’ read another.

A Vodafone source said it is concerned that people in Egypt were under the impression that operators were willingly issuing messages on behalf of the government.

Vodafone said last week that all mobile operators in Egypt had been ordered to suspend services in some areas amid the protests, and that they were obliged to comply under Egyptian law. Some services have since been restored.