Smelyansky added that a subsequent screening discovered another dangerous package.
“Thanks to these measures, we also discovered and removed another parcel containing prohibited and dangerous contents,” he said.
“The control system did its job, but unfortunately five employees were injured. They are receiving all necessary medical care.”
An investigation is ongoing. Smelyansky said he will provide further details when the authorities allow.
“Once again, I appeal to our valued customers: Please do not endanger our employees or your friends and loved ones,” he added.
The State Customs Service said the blast took place during the customs control of international mail being prepared for shipping. Two customs officers and three Ukrposhta workers were hurt.