London, Sept. 23 -- British Prime Minister Boris Johnson on Tuesday announced new restrictions short of a total lockdown as experts raised the Covid-19 alert level to its second highest after the UK reported a sharp increase in coronavirus cases in recent weeks.

Renewed concern over managing the Covid-19 pandemic was prompted by expert modelling that showed new cases doubling every seven days, which could lead to 50,000 day-cases by the middle of October.

The new measures would last at least six months, Johnson told the House of Commons.

The curbs include a 10pm curfew for pubs, restaurants and hospitality centres, which has further unnerved the industry struggling to balance the books in recent months. New fines of up to £10,000 an...