LONDON - Military scientists say a high street insect repellent may offer protection against the Covid-19 virus.

In experiments at the UK’s Defence Science and Technology Laboratory, scientists found that Mosi-guard Natural spray could kill the virus when used either as a spray or as a liquid.

The British daily The Independent says it should only ever be used as an additional measure, alongside a face mask, gloves and other PPE.

Face coverings have become mandatory in indoor spaces in England as of today, with fines of up to £100 for anyone refusing to comply.

Masks are now compulsory in shops, supermarkets, indoor shopping centres, takeaways, banks and post offices, as well as airports and train stations.

New government guidelines published on Thursday state that coverings, such as cloth masks or bandanas, must be worn at all times when in these spaces.

The only exceptions are when sitting down to consume food and drink, though masks must remain on when buying food and drink to take away, The Guardian says.

Police have been given powers to enforce the rules and those failing to comply could be handed fines of up to £100, mirroring the rules for failure to wear a mask on public transport.

However, police forces have said they will only be enforcing the rules as a last resort, and officers will not be patrolling premises, reports the BBC.

Exemptions to the rule include children under 11, and those with disabilities or certain health conditions, such as breathing issues or learning difficulties, that make it harder for them to wear a face covering.