MOSCOW, July 30. /TASS/. A Ukrainian small hydrographic vessel was blown up by a drifting mine in the Danube River estuary, the Russian National Defense Control Center chief, Col. Gen. Mikhail Mizintsev, has said.

In his words, the incident occurred when the ship was "measuring depths of a waterway in the Danube River estuary."

According to the official, 70 foreign ships from 16 countries remain blocked in six ports - Kherson, Nikolayev, Chernomorsk, Ochakov, Odessa and Yuzhny.

"The threat of shelling attacks and the danger of mines, created by the Kiev government's actions, prevent ships from taking to the open sea freely," Mizintsev said, adding that the Kiev government keeps evading discussions on the subject with foreign businesses and ship owners.

"At the same time, there are still risks for maritime navigation and port infrastructure, posed by mines that had broken off from cables," the official added. "The Russian Federation is taking all measures to ensure safety of civilian navigation in the Black Sea and the Sea of Azov.".