A suspected contamination of the drinking water supply has triggered a major public health scare in the western North Macedonia town of Gostivar, after more than a thousand people reportedly sought medical treatment with symptoms of stomach illness.

Hospitals in Gostivar have been overwhelmed by patients suffering from vomiting, diarrhoea and fever. Local media reported that around 1,200 people, including children, sought treatment at Gostivar general hospital, although health authorities have yet to confirm the final number of cases.

The country's Food and Veterinary Agency (AFV) moved quickly on July 17, banning the use of drinking water from the Gostivar water supply system after inspectors found what they described as a potentially dangerous irregularity.

An extraordinary inspection at the water treatment facility in the nearby village of Vrutok uncovered an unauthorised pump installed on the main water pipeline.

According to the agency, the device was illegally injecting water from the Vardar River directly into the municipal water supply without the required permits.

The inspection was carried out jointly by the AFV, the Ministry of Environment, the Public Prosecutor's Office and police forensic experts after prosecutors received complaints from residents and requested an urgent investigation into the safety of the drinking water.

Samples have been sent to the Institute of Public Health for laboratory analysis, and the drinking water will remain banned until authorities confirm it is safe.

The incident has fuelled widespread concern across the town. Residents have taken to social media claiming the outbreak is far larger than officially reported, with some alleging that almost every family has at least one member showing symptoms. Those claims have not been independently verified.

“Throughout history, such facilities have been treated as strategic assets and placed under strict security because a single act of sabotage can jeopardise the water supply of an entire city,” according to a Facebook post.

Newly appointed Health Minister Sasho Klekovski, who visited Gostivar general hospital on July 18, said there would be no declaration of an epidemic until the cause of the illnesses was established.

"More epidemiological surveys are needed to find out who the culprit is," Klekovski said, according to Fokus.

He said the number of patients seeking medical help had remained stable since the first cases appeared on the night of July 13.

"Over 200 citizens present themselves daily at the hospital for intervention. In the last 24 hours, there have been 100 requested interventions in pediatrics and 160 requested interventions in the infectious disease department," Klekovski said.

According to the minister, patients have reported similar symptoms, ranging from mild stomach problems with diarrhoea and vomiting to cases accompanied by fever. Most patients have been treated for dehydration with infusions, vitamins and symptomatic therapy before being sent home.

Meanwhile, police and prosecutors have launched a criminal investigation into the incident. Tetovo police spokesperson Fatmir Rexhepi said investigators are examining whether the case could involve the criminal offence of polluting drinking water under North Macedonia’s Criminal Code.

Authorities are continuing to investigate how the illegal connection was installed and whether it was responsible for the suspected contamination, while residents remain advised not to use water from the Gostivar supply system until laboratory results are available.