"The report from the bomb squad was negative, and no further explosives were found in the flat, which does not pose a threat anymore," the police tweeted. The police are searching for Jiří Dvořák, 66, a tall and slim man with grey hair and a mustache. Dvořák was last seen wearing a black sweatshirt and trousers, white trainers, and a black cross-body bag. He might be driving a blue Hyundai Santa Fe with the registration plate 3AZ 7292.