Kyiv — Ukraine's counteroffensive is grinding on. Video from Ukraine's Azov battalion showed an early morning assault on Russia's defensive lines near the town of Bakhmut. The intense, running gun battles there come months after Moscow-backed mercenaries seized control of the eastern city in a hugely symbolic victory.

They took Bakhmut after some of the war's most brutal fighting, and the ongoing battle around the city, as along much of the hundreds-of-miles-long front line, is bloody and neither side is advancing significantly.

But as Ukraine's counteroffensive grinds to a stalemate on multiple fronts, the military is starting to make important gains further the south. According to U.S. officials, there was "notable" progress near the southern city of Zaporizhzhia over the weekend.

Kyiv's aim is to break through Russia's defenses and march directly south, all the way to the coast on the Sea of Azov. If they manage it, Ukraine would cut off Russia's land access route to the long-occupied Crimean Peninsula. But Moscow has established long barriers across the terrain, full of minefields, tank traps, miles of trenches and other defenses, and that has been slowing Ukraine's advance.

The Kremlin's drone warfare campaign also isn't slowing down. Early Monday, Moscow launched a 3-and-a-half-hour assault on the Danube River port of Izmail, targeting vital Ukrainian infrastructure. Ukraine's military said at least 17 of the Russian drones were taken down by air defense systems, but some hit their targets and damaged buildings.

Izmail has become an important transit route for Ukraine's vast grain exports following Russian President Vladimir Putin's decision in July to withdraw from a U.N. and Turkey-brokered export deal that saw the supplies pass safely through the Black Sea for about a year.

Putin met Monday with Turkish President Recep Tayyip Erdogan as part of efforts to revive the agreement, which saw some 32 million of tons of grain reach global markets through Ukraine's sea ports and helped to ease a global food crisis, according to the U.N.

But it didn't appear that any breakthrough was made, with Putin reiterating complaints about the accord, including accusing Western nations of refusing to ease sanctions on Russian banking and insurance services that Moscow says have severely impacted Russia's own exports and deliveries of agricultural equipment and spare parts.

The restrictions, imposed after Moscow launched its full-scale invasion of Ukraine in February 2022, have also had a major impact on the Russian economy.

Far from the diplomacy — and deep underground — many children were back in school this week in the eastern city of Kharkiv. But life is far from normal in Ukraine's second largest city. Dozens of improvised classrooms for around 1,000 students have been set up in a local subway station.

"We are trying to do everything possible for our children not to feel this war," said the school's director, Ludmyla Usichenko. "We are trying to create a safe environment for them."

As Ukraine's brutal war drags into its 18th month, even educating children means making concessions.

In:
• War
• Bakhmut
• Ukraine
• Russia
• Vladimir Putin
• Volodymyr Zelenskyy

Imtiaz Tyab

Imtiaz Tyab is a CBS News correspondent based in London.

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