Prosecutors have said anyone making threats of coronavirus infection will face serious criminal charges, after reports of police officers, shop workers and vulnerable people being deliberately coughed at by people claiming to have the disease.

The Crown Prosecution Service said such behaviour could constitute common assault, and attacks on emergency workers specifically were punishable by up to two years in prison.

In one incident an RSPCA officer trying to rescue an injured swan was abused and spat at by teenagers who told her to “have corona”.

Max Hill QC, the director of public prosecutions, said: “Emergency workers are more essential than ever as society comes together to tackle the coronavirus pandemic. I am therefore appalled by reports of police officers and other frontline workers being deliberately coughed at by people claiming to have Covid-19.

“Let me be very clear: this is a crime and needs to stop. The CPS stands behind emergency and essential workers and will not hesitate to prosecute anybody who threatens them as they go about their vital duties.”

Quick guide UK lockdown: what are the coronavirus restrictions? Show Hide What do the restrictions involve? People in the UK will only be allowed to leave their home for the following purposes: Shopping for basic necessities, as infrequently as possible

One form of exercise a day – for example a run, walk, or cycle – alone or with members of your household

Any medical need, to provide care or to help a vulnerable person

Travelling to and from work, but only where this is absolutely necessary and cannot be done from home Police will have the powers to enforce the rules, including through fines and dispersing gatherings. To ensure compliance with the instruction to stay at home, the government will: Close all shops selling non-essential goods, including clothing and electronic stores and other premises including libraries, playgrounds and outdoor gyms, and places of worship

Stop all gatherings of more than two people in public – excluding people you live with

Stop all social events, including weddings, baptisms and other ceremonies, but excluding funerals Parks will remain open for exercise, but gatherings will be dispersed.

On Wednesday Darren Rafferty, 45, admitted to three counts of assaulting an emergency worker after claiming to have coronavirus and directing coughs at Metropolitan police officers arresting him for another offence. He will sentenced at Snaresbrook crown court next week.

Another man, David Mott, 40, was jailed on Wednesday after threatening to spit at police officers in Blackburn who had asked him what he was doing out with two others following the government’s announcement of stricter physical distancing rules on Monday night.

Appearing at Blackburn magistrates court, Mott admitted possession of an offensive weapon, possession of a class B drug and threatening behaviour. He was jailed for 26 weeks.

Leanne Honess-Heather, an RSPCA officer, said she was approached by five boys aged between 16 and 17 as she tried to help a stranded swan at Rush Lyvars fishing lake in Hullon Saturday. She said they abused her after she asked them to step back.

“They seemed to take offence to this, which led to two of the group spitting directly into my face, going in my mouth and eyes, as they yelled ‘have corona bitch’ at me,” she said.

Stricter guidance strengthening the CPS’s approach to assaults on emergency workers was published in January after analysis revealed it had prosecuted almost 20,000 cases in the first year in which attacks on emergency workers were made a specific offence.

Police chiefs said on Tuesday that the coronavirus pandemic could “bring out the worst in humanity” after a spate of opportunistic crimes hindered efforts to control the crisis. The theft of oxygen canisters from a hospital in south Manchester, the puncturing of ambulance tyres and the raiding of food banks by thieves were among the “worrying isolated incidents” in recent days raised by the National Police Chiefs’ Council (NPCC).

On Sunday morning, paramedics who arrived at a vehicle preparation centre in Ramsgate, Kent, found holes had been drilled into the tyres of six ambulances. Later the same day a West Yorkshire police officer claimed on Twitter that she and her colleagues had been faced with crowds “spitting on the floor and coughing at us”, and had been pelted with eggs, as they responded to a serious incident.

On Monday three teenagers were arrested after an elderly couple were allegedly coughed at and assaulted in Hertfordshire. Police said the couple were approached by three males, one of whom coughed in their faces, in Paynes Park in Hitchin shortly before 1pm on Friday.