Amid fears of targeting others, British police accuse an ISIS supporter of killing MP Ames

British judicial authorities have charged a British youth of Somali descent with premeditated murder in the crime that killed British MP David Amis last week, while the British Home Office announced that members of Parliament are at "great risk".

On Thursday, prosecutor James Cable told the court that Ali Harbi Ali, 25, the son of a former media advisor to a former Somali prime minister, is a supporter of the Islamic State group, and that he had hatched a plan to kill a parliamentarian years ago.

The accused appeared before Westminster Magistrates Court, speaking only to confirm his name, age and address, and the court extended his detention, and he is due to appear before the Old Bailey Criminal Court on Friday.

The British police confirmed that charges of premeditated murder and preparation of terrorist acts were brought against Ali Harbi.

Earlier, Nick Price, head of the Special Crimes and Anti-Terrorism Division in the Royal Prosecution Department, said, "We will tell the court that this murder has a terrorist connection, and has religious and ideological motives."

Home Secretary Priti Patel said that "the authorities have conducted an independent review of the risk faced by members of Parliament, and that MPs are at great risk."

She added - before Parliament - that although there was no information indicating a specific, imminent or worthy threat to be considered, I must tell the House of Commons that the level of threat faced by members of the House is now significant.

Ames was stabbed several times in the attack, which took place on Friday afternoon in Lay-on-Sea (northeast London) during a meeting with his constituents inside a church, and paramedics tried to rescue him at the scene of the attack, but he died.

The killing of Ames, 69, a member of Prime Minister Boris Johnson's Conservative Party, five years after the murder of Labor MP Jo Cox, who was killed during a meeting with voters in the run-up to the vote on Britain's exit from the European Union in June 2016 - sparked calls Better protection for council members.