There have been multiple reports of “needle spiking” – which involves an injection being administered to someone without their knowledge or consent, usually in a nightclub or bar setting – as opposed to the more commonly-known method of contaminating alcoholic drinks.

Zara Owen, a 19-year-old student in Nottingham, central England, said she woke up after clubbing with a “sharp, agonizing pain in my leg” and “almost zero recollection” of the night before. She walked with a limp for the remainder of the day, she wrote on social media, before finding a “pinprick” and realizing that she had been “spiked” by a needle that had pierced through her jeans.

Thankfully, she added, her friends – who had noticed her behaving strangely – helped her to return safely home.

“The fact that this form of spiking is happening is horrifying, with the memory loss it brought me,” Owen told The Washington Post. “What is supposed to be a fun night leads us to almost fear the unknown.”

Nottinghamshire Police said this week that it had received a total of 15 reports of alleged spiking with a sharp object since Oct. 2, with the majority of reports made by females, in venues across the popular university town. Two men had been arrested so far on “suspicion of conspiracy to administer poison with intent to injure, annoy or aggrieve,” they added on Friday.

Cases have also been reported elsewhere in Britain, mostly among college students, in Glasgow, Exeter and Birmingham.

The reported needle spiking incidents come after two high-profile murders of women on the streets, which have left Britain stunned. The overall number of reported needle spiking incidents remains far below the number of drink spiking incidents thought to occur, and have not yet been linked to other crimes such as rape or theft, but police chiefs have been asked to urgently assess how widespread the attacks are around the country, while the home secretary has also expressed concern.

Women’s safety has been at the forefront of minds in Britain in recent months, following the kidnap and murder of Sarah Everard, a 33-year-old marketing executive who was killed by London police officer Wayne Couzens, and the murder of Sabina Nessa, a 28-year-old teacher who was killed by a man as she walked to meet a friend. Both deaths ignited a national debate on gender-based violence and prompted calls for police reform.

In September, a U.K. watchdog called violence against women “an epidemic” and said authorities should treat it with as much urgency as fighting terrorism. On average, a woman is killed by a man in the United Kingdom every three days, it said.

The reports of needle spiking were “deeply worrying” said Melissa Green, general secretary of the National Federation of Women’s Institutes, a charity. The cases “again remind us that our public spaces are not truly safe for women,” Green told The Post.

Police have also been criticized for their approach – including for their advice to women, following the death of Everard, to shout or wave down a bus if they encounter a lone police officer they do not trust – which some said continued to place the onus on women.

“The W.I. does not agree that it is the responsibility of women to educate themselves or alter their behavior to try and keep themselves safe … what is actually needed is action from the whole of society,” Green added.

The needle spiking cases have also prompted a public petition urging politicians to enact tougher laws to search guests on arrival to nightclubs. As of Saturday, it had garnered more than 165,000 signatories, which will trigger the British parliament to consider the petition for a debate.

Meanwhile, from Wales to Birmingham, female students across the United Kingdom are hosting a “Girls Night In” public campaign over the next two weeks to boycott nightclubs and draw attention to the issue of needle spiking and female safety.

Owen told The Post that she would “like to see more change in nightclubs,” including better searches before people enter.

Meanwhile Nia Gallagher, 20, has been using her TikTok platform – where she has almost 300,000 followers, to spread awareness about spiking incidents and personal safety.

Gallagher said her drink was spiked when she was 18, after she left it briefly unattended while out in a Dublin nightclub. The spiking of her drink left her severely unwell for over a week and wiped her memory, she said, although she made it safely home and was not attacked.

“I let my guard down and that’s why it happened to me,” she told The Post, adding that news of the latest attacks was “really upsetting.”

“A lot of people turned 18 over lockdown so it’s their first time going to nightclubs … so I just wanted to warn people,” she said.

It’s unclear what exact drugs are being administered in the syringes. However, Shirin Lakhani, a cosmetic doctor and former anesthetist, said needles and prescription drugs, such as pain killers and opium-based medicines, are extremely easy to get hold of online and assailants would require little knowledge of how to inject under the skin.

“Needles have gotten really fine now and you can get needles as fine as hairs, so it’s possible not to notice, especially in a club environment with the noise,” she told The Post.

Lakhani said images on social media suggested the attackers were targeting hands in particular, with bruises taking some time to manifest.

“It’s appalling that we have to look after ourselves in this way,” said the doctor and mother of two girls. “It’s another way to carry out misogynistic attacks.”