British Prime Minister Boris Johnson said on Wednesday tougher restrictions brought in last week were starting to have an effect on the spread of COVID in some parts of the country, cautioning that it was still early days.

“What we are now seeing, and it’s very, very important to stress that these are early days, we are now seeing the beginnings of some signs that that is starting to have an effect in many parts of the country, but by no means everywhere and it is early days,” he told parliament.

He also said he did not rule out bringing in even tougher restrictions to try to temper the spread of the coronavirus, which has largely been driven by a new variant.