Soldiers in the tiny Gulf nation of Bahrain opened fire on anti-government protesters Friday, sending at least 50 to hospital as the military ruthlessly cleared away an unwanted mass demonstration that was heading towards a public square in the capital city.

Thousands of protesters were headed towards Manama's Pearl Square when the crackdown started. They were all caught in the chaos, as the soldiers hit them first with tear gas and then with bullets.

"People started running in all directions and bullets were flying," said Ali al-Haji, a 27-year-old bank clerk. "I saw people getting shot in the legs, chest, and one man was bleeding from his head."

Anti-government protester Mohammed Al Maskati told CTV News Channel that the government-controlled media is not providing details on Friday's casualties, but he has heard reports that two people have been killed.

"I was just at the hospital, it's horrible," Al Maskati said in a telephone interview from Manama.

Officials at Manama's Salmaniya hospital said that at least 50 people were injured.

Inside the hospital, some doctors and medics were in tears as they treated the protesters hurt in the violent crackdown.

"This is a war," said Bassem Deif, an orthopedic surgeon who was treating protesters injured by flying bullets.

U.S. President Barack Obama condemned the violence, and urged the country's king in a phone call to show restraint.

Obama talked to King Hamad bin Isa Al Khalifa of Bahrain Friday evening and asked him to hold those responsible for the violence accountable.

Obama said Bahrain must respect the "universal" rights of its people.

Pearl Square is the same location where riot police suppressed prior protests on Thursday. Five people were killed in an incident that Foreign Minister Khalid Al Khalifa later called "regrettable" and which involved tear gas, beatings and shotgun blasts.

Despite the retribution from the government and Bahrain's riot police and soldiers, the protesters continue to take to the streets on a daily basis, pushing for political change.

At present, Bahrain has a popularly elected parliament but the monarchy chooses the prime minister and other key political positions.

Al Maskati said the people want a new constitution and a government that is picked by the public.

"We want a government by the people, a constitution written by the people. Those are our demands," he said.

But the demands of some protesters appeared to go beyond what Al Maskati described on Friday, especially after what happened at Pearl Square on Thursday and Friday.

Ahmed Makki Abu Taki, a protester whose brother was among the five fatalities in the Thursday crackdown, said the people on the street have begun talking about a regime change.

"We used to demand for the prime minister to step down, but now our demand is for the ruling family to get out."

Isa Qassim, the imam at a mosque in the village of Diraz, said the attack on the Pearl Square protesters was a "massacre."

Thousands of worshippers chanted: "The regime must go."

With files from The Associated Press