Swedish police have detained several people and cordoned off an area in Stockholm after a patrol heard suspected gunshots, they said on Friday, with the Israeli embassy located in the closed-off area.
"A police patrol at Strandvagen in Stockholm heard bangs and suspected there had been a shooting," police said on their website, adding that the affected area lay between the capital's Djurgarden Bridge, its Nobel Park and the Oscar Church.
Several people have been detained and an investigation has been launched into a suspected serious weapons crime, they added.
"In connection with the ongoing forensic investigation, findings have been made that strengthen the suspicions that a shooting took place," police said on its website.
Reuters could not immediately reach police and the Israeli embassy for comment.
Swedish news agency TT said police declined to comment on whether there was a link between the incident and the Israeli embassy.
Shortly after the incident in Sweden, French police in Rouen shot dead an armed man who set fire to the city's synagogue, Interior Minister Gerald Darmanin and local officials said.
The incident occurred in central Rouen, 130 kilometers (80.78 miles) northwest of Paris, early on Friday morning, Darmanin said in a post on social network X.
The attacker's identity and motive were still unclear. He was carrying a knife and iron bar, according to local authorities.
France hosts the Olympic Summer Games in two months and recently raised its alert status to the highest level against a complex geopolitical backdrop in the Middle East and Europe's eastern flank.
Elie Korchia, the president of France's Consistoire Central Jewish worshippers body, said police had "avoided another antisemitic tragedy".
Regional broadcaster France 3 said firefighters were on the site. The fire had been brought under control, a Rouen city hall official said.
Rouen's mayor said the Normandy town was "battered and shocked."
The city in 2016 was rocked by an attack later claimed by the Islamic State, when a priest was killed with a knife during service in the town of Saint-Étienne-du-Rouvray, in the southern part of Rouen's urban agglomeration.