LONDON — The government on Tuesday imposed tougher coronavirus restrictions in northwest England, as it voiced fears about rising infection rates among younger people.

Health Secretary Matt Hancock said the “very significant rise” in positive tests to 120 cases per 100,000 people in Bolton, near Manchester, was now the highest in the country.

“The rise in cases in Bolton is partly due to socializing by people in their 20s and 30s. We know this from contact tracing,” he told parliament in a statement.

“And through our contact-tracing system, we have identified a number of pubs at which the virus has spread significantly.”

Hancock announced curbs on hospitality venues in Bolton, including reduced opening hours, and a ban on locals from socializing with others from outside their household.

The latest targeted local restrictions come as the government tries to get the economy moving again after months of lockdown imposed in late March.

It has encouraged people to go back to work and use a government-subsidized restaurant scheme to boost revenues for eateries hit hard by the shutdown.

Critics say such measures have only exacerbated infection rates as young people in particular head out to restaurants with scant regard for social distancing.

Britain has seen more than 41,500 deaths in the coronavirus outbreak — the worst toll in Europe — but the death rate has now fallen to its lowest level since mid-March.

Hancock said there was a “concerning rise” in the number of positive tests among young people, a reminder of the continued threat, given the lack of a vaccine.

He warned that although younger people were less likely to develop serious forms of COVID-19, they could easily pass it to those more vulnerable, particularly the elderly.

There is also concern about the long-term effects of COVID-19, and the threat of new cases coming from abroad.

A King’s College London survey, published on Tuesday, found 300,000 people reporting symptoms lasting more than one month, and 60,000 who had been ill for more than three months.

“This is not over,” Hancock concluded. — Agencies