LONDON — In an attack that raised new fears of terrorism in Britain, a man walking near a military barracks in south London on Wednesday was rammed by a car and then hacked to death by two knife-wielding assailants, according to witness accounts carried by British news media.

British officials did not identify the victim, but the French president, Francois Hollande, referred to him as “a soldier” in expressing France’s sympathy to the visiting British prime minister, David Cameron, who had been en route to Paris from Brussels when the attack took place.

The two suspects were shot and wounded by police, officials said, and were in two separate hospitals under police guard, one in serious condition. One of the men shouted “Allahu akbar,” or “God is great,” as the attack proceeded, government officials said.

Cameron, at a news conference at the Elysee Palace in Paris, said the killing was “an appalling murder” and “absolutely sickening.”

“There are strong indications that it is a terrorist incident,” Cameron said. He interrupted his European tour to return to London on Wednesday night.

ITV News showed a video taken with a cellphone at the scene in Woolwich in which a man who appears to be in his 20s or early 30s holds a cleaver in one of his bloodied hands. He offers what seems to be a political message before the police arrive.

“I apologize that women had to see this today, but in our lands women have to see the same thing,” he says. “You people will never be safe. Remove your governments! They don’t care about you.” He then refers to what appeared to be a motive for the attack, saying that it had been carried out “because of what’s going on in our own countries.”

The BBC reported Wednesday night that at least one of the two men had been identified by British security officials as having family origins in Nigeria.

Organizations representing Britain’s 2.5 million Muslims were quick to condemn the attack. “No cause justifies this murder,” the Muslim Council of Britain said in a statement on behalf of the network of mosques, schools and charities it represents. It described the killing in Woolwich as “a barbaric act that has no basis in Islam,” and added that the “vast majority of British Muslims acknowledge the armed forces for the work they do.”

The assault took place near a heavily-trafficked junction, a short walk from the London headquarters of the Royal Artillery, a unit that has deployed soldiers, including tank units, to Iraq and Afghanistan. A primary school is nearby, and witnesses said some of those who had seen the attack were parents and children returning home.

A small blue car — apparently the vehicle used to ram the victim — appeared to have hit a telephone pole after mounting the sidewalk. Photographs and TV footage from the scene showed extensive damage to the car’s hood and windshield.

Witnesses said two men had gotten out and attacked the prone victim with large bladed weapons. Some said the men had beheaded him.

A number said the victim was wearing a T-shirt labeled with the words Help for Heroes, the name of a charity that supports some of the thousands of British military personnel who have returned wounded from Afghanistan and Iraq, and to the families of the more than 600 servicemen and women who have been killed in those conflicts.

A man who said he had seen the entire attack told the BBC that the assailants had lingered at the scene, talking to passers-by about what they had done.

Some witnesses said a man had leapt from an unmarked car and aimed a handgun at the assailants, shouting to pedestrians to clear the area.

The witness who said he had seen the full attack said a policewoman with a handgun fired on the two suspects after one of them rushed toward a group of police officers.

Britain has suffered more than any other country in Northern Europe from Islamic terrorist plots in recent years, and it has worked assiduously to prevent more. Security officials have said that at any given time they are tracking hundreds of young men in extremist networks.

But small-scale attacks can be hard to detect. The SITE Intelligence Group, which monitors jihadi websites, distributed a posting from one Wednesday after the London killing. Dating from July 2011, the message on Shumukh al-Islam, a militant website that has been linked to al-Qaida, urges followers to mount “lone-wolf operations” that might include beheadings.