Queen Elizabeth II arrived in Manchester to visit children and young people injured in Monday's terror bombing at the Manchester Arena.

As well as meeting casualties recovering and being treated for their injuries at the Royal Manchester Children's Hospital on Thursday, the Queen spoke to doctors and nurses, Xinhua news agency reported.

The hospital is treating 14 injured children, with five of them described as critically ill.

Her visit came as NHS England reported that the number of people who have received in-patient hospital treatment as a result of injuries sustained in Monday's attack has reached 116.

An NHS spokesman said 23 of the injured are currently in critical care suffering from serious injuries.

The Queen's arrival came shortly after more than 1,000 people gathered in the city's St Ann's Square during a nationwide one-minute silence. The crowd stood alongside city leaders as a tribute to the dead and injured.

In London, British Prime Minister Theresa May chaired a meeting of the emergency Cobra committee and said later that the threat level will remain at "critical" in Britain, indicating a possible imminent attack.

May said eight suspects remained in custody as part of the investigation by Greater Manchester Police.

A woman arrested at an apartment block in the city has been released. All of those being held at police stations in Manchester are male. The eight include two men arrested by counter terror police on Thursday morning, one in Manchester and another at an undisclosed location.