Great Britain lowered its security threat level from “critical” to “severe” on Saturday, Prime Minister Theresa May said. >> Read more trending news Earlier, police hunting a suspected network behind Salman Abedi, the bomber who killed 22 people on Monday night during a concert in Manchester, said they had made two further arrests overnight as they closed in on other possible cell members, Reuters reported. As a result, soldiers who have been assisting police would be withdrawn from Britain's streets at midnight on Monday. 'A significant amount of police activity has taken place over the last 24 hours and there are now 11 suspects in custody,' May said. May cautioned, however, that the lesser threat is still a dangerous one. 'The public should be clear about what this means. A threat level of severe means an attack is highly likely,” she said. “The country should remain vigilant.' The threat assessment has returned to the level it was at prior to the Manchester attack. In Manchester, events planned around the spring bank holiday will go ahead with additional security, including a significant number of armed officers, police said. British officers do not usually carry guns, CNN reported. Events include the Manchester Games, the Great Manchester Run, and a stadium show by bands including The Courteeners, all of which are likely to attract big crowds. This weekend also marks the start of Ramadan, the holiest month of the Muslim calendar, CNN reported.