Supporters of Egypt's ousted president Mohamed Morsi carry a wounded man during clashes with security forces in Cairo. Photograph: Hassan Ammar/AP
New violence erupted in central Cairo and across Egypt on Friday on a "day of rage" called by the Muslim Brotherhood to protest against the removal of President Mohamed Morsi and the killings of hundreds of his supporters by the military-backed government.
By nightfall, at least 20 and as many as 45 people had been reported shot dead in fierce street fighting in the centre of the capital, where machine gun fire was heard as a military helicopter flew overhead. Security officials said the death toll rose to at least 60 people killed across the country: 52 civilians and eight police officers. The latest death toll also included eight people confirmed killed in Damietta, four in Ismailia, and 13 elsewhere in the country.
TV cameras caught unidentified gunmen in civilian clothes firing automatic rifles on the May 15 bridge that crosses Zamalek in the heart of Cairo, where many foreigners and wealthy Egyptians live. People jumped off the bridge to escape the shooting. Uniformed police were nowhere to be seen. Firing also broke out outside a luxury hotel on the banks of the Nile near Tahrir Square.
On Friday night , the Brotherhood called on its supporters to continue daily protests across the country, but it urged its supporters to protest peacefully. "The struggle to overthrow this illegitimate regime is an obligation," it said in a statement.
The interior ministry had warned that security forces had been authorised to fire live ammunition at anyone targeting police and state institutions.
The Guardian saw dozens of bodies lying on the bloodstained floor of Cairo's al-Fath mosque on Ramses Square, which had been turned into a field hospital. Medical volunteers were overwhelmed by the scale of the blood-letting.
Gehad al-Haddad, a Brotherhood spokesman, denounced what he called "military coup criminals" after the group said 45 people had been killed in Ramses Square and urged supporters to withdraw to avoid further casualties.
On another day of high drama and now routine bloodshed, it was often hard for observers to keep up with the sheer pace of events. "It's impossible to follow up on everything that is taking place," tweeted commentator Bassem Sabry. "It is happening too fast, and everywhere."
Amid rising international concern, the French president, François Hollande, and German chancellor, Angela Merkel, called for a meeting of EU foreign ministers to co-ordinate a response. The EU tried but failed to mediate between the Egyptian government and the Islamist movement to secure a peaceful end to the two mass protest sit-ins that were broken up in Cairo on Wednesday, leaving at least 580 dead.
The Foreign Office (FCO) said it remained "deeply concerned" about the situation, and deplored the latest loss of life. "The UK continues to call for an end to violence and for a return to peaceful dialogue," a spokesman said.
President Barack Obama announced on Thursday the cancellation of joint US-Egyptian military exercises, scheduled for next month. But he failed to react to demands that Washington should cut its $1.3bn (£831.2m) in aid to the powerful Egyptian armed forces.
"Our traditional co-operation cannot continue as usual when civilians are being killed in the streets and rights are being rolled back," Obama said. The Egyptian presidency retorted in a statement that Obama's words were "not based on fact" and would "embolden armed groups".
The presidency defended its actions as being in the spirit of the 2011 revolution, which overthrew Hosni Mubarak. Critics argue that the emergence of Egypt's new military-backed regime, and a corresponding return to favour of the country's once-hated police force, represents a return to the Mubarak era.
State media called for a new "external campaign" to resist international pressure for dialogue and reconciliation with the Brotherhood. Several newspapers lambasted Mohamed ElBaradei, the liberal figure who resigned as vice-president in protest at Wednesday's bloodshed. In one caricature, ElBaradei was portrayed as stabbing Egypt in the back.
Khaled Dawoud, a spokesman for the anti-Morsi National Salvation Front, followed ElBaradei and announced his departure on Friday, citing the failure of the NSF to condemn state violence against the Brotherhood.
Saudi Arabia, evidently delighted at the demise of the Islamists, called on Arab countries to resist attempts to destabilise Egypt. "The Kingdom of Saudi Arabia, its people and government, stood and stands today with its brothers in Egypt against terrorism," King Abdullah said in a message read out on national television. "All those who meddle in Egypt's internal affairs are inflaming strife."
The UN said its under-secretary general for political affairs, Jeffrey Feltman, would visit Egypt next week to meet officials including Brotherhood representatives.
Anti-Brotherhood sentiment has deepened since Wednesday after several reports of revenge attacks on policemen and Christians across the country – reinforcing the image of Islamists as terrorists. Morsi's removal had broad backing, but some of his supporters havescapegoated Egypt's Coptic Christian community – which forms about 10% of the population – for supporting his overthrow.
The Brotherhood denied responsibility despite the sectarian rhetoric of many members. A spokesman said the Iman mosque in north-east Cairo, which had been filled with the rotting corpses of people who died on Wednesday, was stormed by armed security officials during the new overnight curfew imposed along with restored emergency laws.
Against a background of concern about the spreading and escalating violence, security officials said explosives were detonated on railway tracks between Alexandria and the western Mediterranean Sea province of Marsa Matrouh. There were no injuries and no trains were damaged in the attack.
The FCO said it was keeping its travel advice on Egypt's Red Sea resorts under continuous and intense review as Germany, Sweden and Switzerland joined the list of countries recommending their citizens not to go to any part of the country.
An estimated 40,000 Britons are still on holiday in Egypt and companies say normal flights between the UK and resorts will continue until the Foreign Office changes its stance.
The government has already warned against all but essential travel to most of Egypt, including Cairo, Alexandria and Luxor. The resorts are exempt from such advice because of "enhanced security measures".
But the Foreign Office said: "We have urged British nationals to obey the regulations set out by the local authorities and the curfew, if they are in a resort affected by this."