Updated

Police have charged a man with murder in the killing of a British soldier in a suspected Islamic extremist attack in broad daylight on a London street.

Michael Adebowale, 22, was charged late Wednesday by counterterrorism officers and will appear in court on Thursday, police said. He is one of two main suspects in the killing of Lee Rigby, 25, who was struck by a car and stabbed to death last week near his barracks in southeast London's Woolwich district.

Gruesome images that emerged after the attack showed two men wielding bloody knives and meat cleavers. Both men were shot and wounded by police.

Suspect Michael Adebolajo, 28, remains hospitalized in stable condition. Adebowale was discharged from a hospital Tuesday and taken into custody. Adebowale also was charged with a firearms offense related to possessing a 9.4 mm revolver with the intent "to cause persons to believe that unlawful violence would be used," police said in a statement announcing the charges.

The charges, coming just hours after police said Rigby's autopsy showed he died from "multiple incised wounds," shed further light on the frenzied attack.

Witnesses reported seeing the soldier struck by a car, then set upon by two men wielding long knives and cleavers. Adebolajo, bloodied and clutching a cleaver, was seen in a video boasting about the attack and railing against the government.

The attack has raised questions about whether Britain's intelligence services could have done more to prevent Rigby's murder. British officials said the two main suspects had been known to them for some time as part of previous investigations.

Kenyan police have said they believed Adebolajo, a British citizen, had earlier associated with a radical Kenyan Muslim cleric who tried to help him join an al-Qaida-linked rebel group in neighboring Somalia.

Police said an inquest on Rigby's death will open Friday. In Britain, inquests are conducted to establish the circumstances surrounding unexpected or violent deaths.

Ten people have been arrested in the case, including the two main suspects. Two were released and several others have been set free on bail pending further inquiries.

One of the men arrested for questioning in the case released a statement through his lawyer Wednesday proclaiming his innocence. Hayden Allen, 21, said he wanted to send his condolences to Rigby's family.

"My family are wholly uninvolved," said Allen, who has not been charged and is free on bail. "I ask that the police continue to investigate and that my family be allowed without harassment to continue their lives."

Rigby's murder has raised racial enmities in many parts of England, with far-right groups mobilizing to protest. The English Defense League, a right-wing group with strong anti-Islam leanings, has held a series of protests, while Muslim community organizations have reported a surge in attacks and harassment.

One mosque in the northern England town of Grimsby was firebombed, and the word "ISLAM" was daubed in big red letters across the Royal Air Force Bomber Command memorial in London's Green Park, near Buckingham Palace.

Two people have been charged in the arson attack. It was unclear who was responsible for the graffiti.

Hackers have also posted a purported list of English Defense League leaders and supporters online. The list was at least partially genuine, according to English Defense League supporter Glen Warren, 32, whose name and phone number were among those posted.

Amid the unrest, British prison officers have been warned to be on the lookout after a hostage drama blamed on extremist Muslim inmates, British newspapers reported Wednesday.

An email to high-security prisons and young offenders' institutes warned that Sunday's incident at Full Sutton detention facility in the northern England region of Yorkshire was linked to religious extremism and warned of an increased risk of attacks at other institutions, according to several British papers, including The Yorkshire Post and The Times.

"Three Muslim prisoners took an officer hostage in an office. Their demands indicated they supported radical Islamist extremism," the letter was quoted as saying. "All staff are reminded to remain vigilant to the increased risk of potential attacks on prison officers inspired by these and last Wednesday's events."

The hostage-takers' demands have not been disclosed. Britain's Ministry of Justice declined to comment on the email.