In Poland, fire departments are checking the condition of the country's bomb shelters and compiling an inventory, Deputy Interior Minister Maciej Wasik said.

While Poland assures citizens that its place in the alliance guarantees their safety, events in neighboring Ukraine have drawn attention to the need to be prepared for the possibility of a missile attack.

"We have 62,000 of these facilities all over the country," Wasik told the private television station Polsat News.  "Firefighters are checking their condition and fitness for use. If necessary, we will take measures to adapt them."

Wasik said Poland is not under threat, but is preparing for a worst-case scenario. "This is a routine activity," he said. "This action was planned some time ago."

The vetting process will last two months.