Reports of domestic violence in London have risen by a third in the last six weeks, police said on Friday, urging victims to speak out and promising they will not be punished if they need to break social distancing guidelines.

Britain is enduring its fifth week of a national lockdown, with businesses shuttered and citizens ordered to stay at home as the government tries to prevent the spread of the coronavirus and stop health services becoming overwhelmed.

However, London's Metropolitan Police service said that while the lockdown was vital to the national effort it has also left "current and potential victims of domestic abuse even more vulnerable and isolated."

The force said calls about domestic abuse had gone up by around a third in the last six weeks and that its officers were making around 100 arrests a day for such offences. There was a 9% rise in recorded incidents compared to a year ago.

"No-one who is experiencing domestic abuse should feel that they have to suffer in silence," said senior police office Sue Williams.

"Victims should be assured that they can leave their homes to escape harm or seek help, and they will not be penalized in any way for not maintaining social distancing, or otherwise breaching COVID-19 restrictions."