This image released by the Romanian Ministry of Defense (MAPN), shows members of the army's engineering units building concrete shelters in the village of Plauru, on the Danube river border between Romania and Ukraine on Tuesday, Sept. 12, 2023. In the Danube village of Plauru, which is situated opposite Ukraine's Danube port of Izmail, Romania's defense ministry has erected prefabricated concrete shelters for residents, measuring 9.6 meters long, 2 meters wide inside, and 1.5 meter high (about 31 feet long, 6.5 feet wide and 5 feet high). (Romanian Defense Ministry MAPN via AP)

This image released by the Romanian Ministry of Defense (MAPN), shows a member of the army's engineering units walking next to concrete shelters built in the village of Plauru, on the Danube river border between Romania and Ukraine on Tuesday, Sept. 12, 2023. In the Danube village of Plauru, which is situated opposite Ukraine's Danube port of Izmail, Romania's defense ministry has erected prefabricated concrete shelters for residents, measuring 9.6 meters long, 2 meters wide inside, and 1.5 meter high (about 31 feet long, 6.5 feet wide and 5 feet high). (Romanian Defense Ministry MAPN via AP)

This image released by the Romanian Ministry of Defense (MAPN), shows a concrete shelter built by the army's engineering units in the village of Plauru, on the Danube river border between Romania and Ukraine on Tuesday, Sept. 12, 2023. In the Danube village of Plauru, which is situated opposite Ukraine's Danube port of Izmail, Romania's defense ministry has erected prefabricated concrete shelters for residents, measuring 9.6 meters long, 2 meters wide inside, and 1.5 meter high (about 31 feet long, 6.5 feet wide and 5 feet high). (Romanian Defense Ministry MAPN via AP)