LONDON — Britain lowered its terrorist-threat level but simultaneously expanded background checks for skilled immigrants yesterday. Authorities continued to monitor about 1,600 people believed to be plotting terrorist attacks.
The reduced terrorist-threat level was based on the premise that the main plotters of failed bombings in London and Glasgow — all Muslim employees of the National Health Service — have been arrested.
“We’ll expand the background checks that have been done where there are highly skilled migrant workers coming into this country,” Prime Minister Gordon Brown told the House of Commons yesterday.
With the terrorism threat level dropped to “severe” from “critical” — the highest on a five-point scale — reports of a chilling warning before Friday and Saturday’s attempted bombings surfaced.
“Those who cure you are going to kill you.”
That, a British priest said yesterday, was the vague warning made to him in Jordan by a purported al Qaeda leader months before the failed car bombings in London and Glasgow that have been linked to a group of foreign Muslims working as doctors in Britain.
Six of eight persons in custody are physicians, one a medical student and another a medical assistant.
Several of the arrested suspects were on a watch list compiled by the domestic intelligence agency MI5, a British government security official said, indicating their identities had been previously logged by agents. The official did not say why they were put on the watch list.
“Some, but not all, have turned up in a check of the databases, but they are not linked to any previous incident,” the security official said, speaking on condition of anonymity because of the sensitivity of the material.
British authorities have said the attacks bore hallmarks of an al Qaeda operation, but security officials say investigators are still trying to determine whether there was a direct link between the suspected plotters and an outside mastermind.
No one has yet been charged in the plot.
Canon Andrew White, a senior Anglican priest who works in Baghdad, said he met a purported al Qaeda leader April 18, after holding talks with Sunni Muslim tribal and religious leaders in the Jordanian capital, Amman. The priest meets regularly with extremists in an attempt to calm Iraq’s sectarian violence.
“It was like meeting the devil,” he told the Associated Press in a phone interview from Baghdad. “He talked of destroying Britain and the United States and then said, ‘Those who cure you are going to kill you.’ ”
Mr. White said he did not understand the threat’s significance at the time but passed the general threat along to Britain’s Foreign Office. He did not mention the comment, which could be interpreted as hinting at the involvement of doctors in a terror plot.