Dozens of people have been injured after armed troops opened fire on anti-government protesters in Bahrain's capital, according to reports.
Eyewitnesses reported seeing army units shooting above the protesters and then at them, as they attempted to drive them back from security cordons near Pearl Square.
Around 15 people are injured, according to Sky sources.
It comes after thousands of people attended the funerals of four people killed in recent unrest, chanting slogans and calling for change.
There had been fears that the gatherings would spark further violent clashes.
At least five people died and more than 200 were injured on Thursday when security forces drove protesters out of a makeshift camp in the Middle Eastern country's capital, Manama.
Bahrain's leaders have ordered military tanks onto the streets and warned demonstrators to stay away from the city centre.
Top Shi'ite cleric Sheikh Issa Qassem told worshippers during Friday prayers that the police's deadly assault on the protesters was a "massacre".
Many Bahrainis have told Sky News they are more determined than ever for the country's monarchy and government to be removed, but they are keen for their demonstrations to be peaceful.
A huge section of the crowd at the funeral procession in the village of Sitra, on Manama's outskirts, was made up of women - unusual for a country where they are traditionally kept out of sight.
One said: "I'm not concerned, I'm very optimistic. We are calling for transformation."
After allowing several days of rallies by disaffected Shia Muslims, the royal rulers of the island nation, which lies east of Saudi Arabia, unleashed riot police in the capital on Wednesday night.
They stormed a protest encampment at the Pearl roundabout in the early hours of Thursday, firing tear gas, beating demonstrators and blasting them with shotgun sprays of birdshot.
The willingness to resort to violence against largely peaceful demonstrators has been seen as a sign of how deeply the Sunni monarchy - which rules over a Shia majority - fears prolonged protests.
Authorities have also escalated their physical attacks on media trying to report the unrest, according to the Committee to Protect Journalists.
Mohammed Abdel Dayem, the CPJ's Middle East and North Africa programme coordinator, said: "Governments throughout the Middle East and North Africa cannot deny their citizens coverage of thse momentous events across the region.
The latest uprising appears to have been inspired by a wave of anti-government unrest sweeping the Middle East and North Africa.
Nearly three weeks of protests in Egypt resulted in president Hosni Mubarak stepping down last Friday after some 30 years in power.
Tunisia's president quit in January and fled the country following violent clashes. There have also been deadly protests this week against Colonel Gaddafi's regime in Libya.
Bahrain's foreign minister Khalid Al Khalifa said the military crackdown was necessary because the demonstrators were polarising the country "and pushing it to the brink of the sectarian abyss".
Speaking to reporters after an emergency meeting with his Gulf counterparts in Manama, he called the violence regrettable and said the deaths would be investigated.
He defended the retaliation by the authorities by saying authorities chose to clear people from the landmark Pearl roundabout by force at 3am, when fewer people were there, to reduce the possibility of casualties.
Many of the protesters were sleeping and said they received little warning of the assault.
Dozens are said to be still missing following the early morning raid, prompting fears that the true death toll is much higher than being reported by officials.
In the wake of the bloodshed, angry demonstrators at one hospital chanted: "The regime must go!"
The White House has called for restraint on both sides. Bahrain is a key ally of the West and the base of the US Navy's 5th Fleet.
The fallout from the protests is also being felt in the sporting world, with next month's Bahrain Grand Prix at risk of being cancelled.