Russian police have detained a man suspected of involvement in a blast that tore through a café in St Petersburg on Tuesday.

Blast rattles downtown café

The explosion set off a fireball inside the popular downtown eatery, badly damaging the building and prompting an emergency response that saw dozens of firefighters and medics on site.

According to the city's emergency services, the blast occurred shortly after noon, when the venue was filled with patrons. Investigators say a small improvised device was placed near the kitchen area.

Survivors described the shock of the blast, with broken glass raining onto the street and a thick plume of smoke filling the square. Several victims were taken to hospitals with injuries ranging from cuts to shrapnel wounds.

St Petersburg café street after blast with broken glass and smoke

Police detain suspect

The St Petersburg Police Department announced that a 32‑year‑old male, identified only by his surname, was taken into custody late Wednesday after a three‑day search. Officials said the suspect is being questioned about possible links to extremist groups, but no motive has been confirmed.

Security implications

The incident revives memories of previous attacks in Russia's major cities, including the 2017 metro bombing in Saint‑Petersburg and the 2022 concert hall strike in Moscow, prompting renewed debate over domestic security measures.

Kremlin spokesperson Dmitry Peskov, speaking to state media, urged the public not to succumb to fear and pledged that "all necessary steps" will be taken to prevent further violence. The statement came as the Federal Security Service stepped up patrols in the city centre.

Analysts say the detention could be an attempt by authorities to demonstrate swift action, but warn that without a clear picture of the network behind the device, the threat may persist. Investigators are examining CCTV footage and forensic evidence as the probe continues.

The next hearing for the suspect is scheduled for next week, and police have said they will release more details as they become available.