Ukrainian military engineer with the call sign "Lizard" walks near fortifications, including "dragon's teeth" and barbed wire, that he helped to build in a field near the front line outside Kupiansk, amid Russia’s attack on Ukraine, December 28, 2023. REUTERS/Thomas Peter TPX IMAGES OF THE DAY Photo: Thomas Peter/REUTERS
Danylo, commander of an engineering and sapper company of the Ukrainian Armed Forces, inspects pyramidal anti-tank obstacles known as 'dragon's teeth' before installing them into a new fortification line, amid Russia's attack on Ukraine, in Zaporizhzhia region, Ukraine March 11, 2024. REUTERS/Stringer Photo: Stringer/REUTERS
A view of newly built anti-tank fortifications, called "dragon's teeth" and razor wire, amid Russia's attack on Ukraine, near the town of Bakhmut in Donetsk region, Ukraine March 8, 2024. REUTERS/Oleksandr Ratushniak Photo: OLEKSANDR RATUSHNIAK/REUTERS
A view of newly built anti-tank fortifications, called "dragon's teeth" and razor wire, amid Russia's attack on Ukraine, near the town of Bakhmut in Donetsk region, Ukraine March 8, 2024. REUTERS/Oleksandr Ratushniak Photo: OLEKSANDR RATUSHNIAK/REUTERS
A satellite image shows an overview of fortifications built by the Russian army, including "dragon's teeth" and trenches, stretching across the town of Tokmak, amid Russia's attack on Ukraine, in Zaporizhzhia region, Ukraine, May 12, 2023. Maxar Technologies/Handout via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. NO RESALES. NO ARCHIVES. MANDATORY CREDIT. DO NOT OBSCURE LOGO Photo: MAXAR TECHNOLOGIES/REUTERS
A satellite image shows an overview of rows of fortifications called "dragon's teeth" and trenches built by the Russian army in the Vasylivka district, amid Russia's attack on Ukraine, in Zaporizhzhia region, Ukraine, March 4, 2023. Maxar Technologies/Handout via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. NO RESALES. NO ARCHIVES. MANDATORY CREDIT. DO NOT OBSCURE LOGO REFILE - CORRECTING DATE FROM "NOVEMBER 15, 2022" TO "MARCH 4, 2023\ Photo: MAXAR TECHNOLOGIES/REUTERS
A satellite image shows an overview of fortifications built by the Russian army, including "dragon's teeth" and trenches, stretching along the beach, amid the Russia-Ukraine conflict, in Yevpatoriya, Crimea March 12, 2023. Maxar Technologies/Handout via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. NO RESALES. NO ARCHIVES. MANDATORY CREDIT. DO NOT OBSCURE LOGO Photo: MAXAR TECHNOLOGIES/REUTERS
A satellite image shows an overview of fortifications built by the Russian army, including "dragon's teeth" and trenches, stretching across the town of Tokmak, amid Russia?s attack on Ukraine, in Zaporizhzhia region, Ukraine, May 12, 2023. Maxar Technologies/Handout via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. NO RESALES. NO ARCHIVES. MANDATORY CREDIT. DO NOT OBSCURE LOGO Photo: MAXAR TECHNOLOGIES/REUTERS
Fortifications built by the Ukrainian army, including "dragon's teeth" and razor wire, stretch across a field near the frontline town of Kupiansk, amid Russia’s attack on Ukraine, in Kharkiv region, Ukraine February 19, 2024. REUTERS/Sofiia Gatilova Photo: Stringer/REUTERS
Fortifications built by the Ukrainian army, including "dragon's teeth" and razor wire, stretch across a field near the frontline town of Kupiansk, amid Russia’s attack on Ukraine, in Kharkiv region, Ukraine February 19, 2024. REUTERS/Sofiia Gatilova Photo: Stringer/REUTERS
A view of newly build anti tank fortifications, named 'dragon's teeth' and razor wire, amid Russia’s attack on Ukraine, near Russian border in Chernihiv region, Ukraine, January 10, 2024. REUTERS/Gleb Garanich Photo: GLEB GARANICH/REUTERS
A view of newly build anti tank fortifications, named 'dragon's teeth' and razor wire, amid Russia’s attack on Ukraine, near Russian border in Chernihiv region, Ukraine, January 10, 2024. REUTERS/Gleb Garanich Photo: GLEB GARANICH/REUTERS
Ukrainian servicemen check newly build anti tank fortifications, named "dragon's teeth" and razor wire, amid Russia's attack on Ukraine, near Russian border in Chernihiv region, Ukraine, January 10, 2024. REUTERS/Gleb Garanich Photo: GLEB GARANICH/REUTERS
Serhii Naiev, Commander of the Joint Forces of the Armed Forces of Ukraine and Ukrainian servicemen check newly build anti tank fortifications, named "dragon's teeth" and razor wire, amid Russia’s attack on Ukraine, near Russian border in Chernihiv region, Ukraine, January 10, 2024. REUTERS/Gleb Garanich Photo: GLEB GARANICH/REUTERS
Ukrainian servicemen check newly build anti tank fortifications, named "dragon's teeth" and razor wire, amid Russia's attack on Ukraine, near Russian border in Chernihiv region, Ukraine, January 10, 2024. REUTERS/Gleb Garanich Photo: GLEB GARANICH/REUTERS
Ukrainian servicemen check newly build anti tank fortifications, named 'dragon's teeth' and razor wire, amid Russia’s attack on Ukraine, near Russian border in Chernihiv region, Ukraine, January 10, 2024. REUTERS/Gleb Garanich Photo: GLEB GARANICH/REUTERS
Fortifications, including “dragon's teeth” and barbed wire, built by the Ukrainian army stretch across a field near the front line outside Kupiansk, amid Russia’s attack on Ukraine, December 28, 2023. REUTERS/Thomas Peter Photo: Thomas Peter/REUTERS
Fortifications, including “dragon's teeth” and barbed wire, built by the Ukrainian army stretch across a field near the front line outside Kupiansk, amid Russia’s attack on Ukraine, December 28, 2023. REUTERS/Thomas Peter Photo: Thomas Peter/REUTERS