Slovak Prime Minister Robert Fico has been shot and wounded, according to local media reports.
Mr Fico was shot in front of a cultural community centre in the town of Handlova, where a government meeting had been held, reports say.
Several shots were heard, according to journalists on the scene.
The Slovak leader has been taken to hospital and his alleged assailant detained by police.
Handlova is around 180km (112 miles) north-east of the capital Bratislava.
A video showed several men rushing to detain the suspect just outside the cultural centre in Handlova. The BBC has not yet verified the footage.
In her initial reaction to the shooting, Slovakia's outgoing president Zuzana Caputova said she was shocked by the "brutal and ruthless" attack on the prime minister and wished him strength to recover.
Mr Fico returned to power in Slovakia after elections last September, at the head of a populist-nationalist coalition.