KYIV, Ukraine (AP) — Four more ships carrying agricultural cargo held up by the war in Ukraine received authorisation Sunday to leave the country’s Black Sea coast as analysts warned that Russia was moving troops and equipment in the direction of the ports to stave off a Ukrainian counteroffensive.

The body overseeing an international deal intended to get some 20 million tons of grain out of Ukraine and to feed millions of impoverished people who are going hungry in Africa, the Middle East and parts of Asia said the loaded vessels were cleared to depart from Chornomorsk and Odesa.

Ukraine, Russia, Turkey and the United Nations signed agreements last month to create an 111 nautical mile sea corridor that would allow cargo ships to travel safely out of ports that Russia’s military had blockaded and through waters that Ukraine’s military had mined. Implementation of the deal, which is in effect for four months, has proceeded slowly since the first ship embarked on August 1.

For the last four months of the war, Russia has concentrated on capturing the Donbas region of eastern Ukraine, where pro-Moscow separatists have controlled some territory as self-proclaimed republics for eight years. Russian forces have made gradual headway in the region bordering Russia while launching missile and rocket attacks to curtail the movements of Ukrainian fighters elsewhere.

Over the past day, five civilians were killed in Russian and separatist firing on cities in the Donetsk region, the part of Donbas still under Ukrainian control, the regional governor, Serhiy Haidai, reported. He and Ukrainian government officials repeatedly have urged civilians to evacuate the province.

In a weekend analysis, Britain’s Defense Ministry said the Russian invasion that started February 24 “is about to enter a new phase” in which the fighting would shift west and south to a roughly 350-kilometre (217-mile) front line that extends from near the city of Zaporizhzhia to Russian-occupied Kherson.

Kherson, located on the Dnieper River near its mouth with the Black Sea, came under Russian control early in the war and Ukrainian officials have vowed to retake it. Kherson is located 227 kilometres (141 miles) from Odesa, home to Ukraine’s biggest port, so the conflict escalating there could have repercussions for the international grain deal.

The city of Mykolaiv, an important shipbuilding center that Russian forces bombard daily, is even closer to Odesa. The Mykolaiv region’s governor, Vitaliy Kim, said an industrial facility on the regional capital’s outskirts came under fire early Sunday.

Ukraine’s nuclear power plant operator, Energoatom, reported that Europe’s largest nuclear power plant, which is located in the country’s southeast, came under Russian fire late Saturday. It said the shelling damaged three radiation monitors around the storage facility for spent nuclear fuels and that one worker was injured.

For months, Russian forces have occupied the Zaporizhzhia Nuclear Power Station, which is located on the left bank of the Dnieper River in the city of Enerhodar. Rafael Grossi, director general of the International Atomic Energy Agency, recently said he was worried the way the plant was being run and the fighting taking place around it posed grave health and environmental threats.

“Every principle of nuclear safety has been violated” at the plant, Grossi said Tuesday.

Russian soldiers at the plant took shelter in bunkers before Saturday’s attack, according to Energoatom.

On Saturday, Russian forces launched airstrikes, fired artillery and redistributed other weaponry as part of attempts to defend their positions in occupied areas, according to the Institute for the Study of War, a Washington think tank.

Citing local Ukrainian officials, the institute said the Russians “are continuing to accumulate large quantities of military equipment” in a town across the Dnieper River from Kherson. The preparations appeared designed to defend logistics routes to the city and to establish defensive positions on the river’s left bank, the think tank said.

Ukrainian officials were initially skeptical of a grain export deal, citing suspicions that Moscow would try to exploit shipping activity to mass troops offshore or to send long-range missiles from the Black Sea, as it has done multiple times during the war. The agreements approved last month call for ships to leave Ukraine under military escort and to undergo inspections.

Ships leaving Ukraine are inspected by teams made up of officials from the three countries and the UN to make sure they carry only grain, fertilizer or food and not any other commodities. Inbound vessels are checked to ensure they are not carrying weapons.

The Joint Coordination Center, which is responsible for managing the deal, said that three cargo ships that left Friday passed their inspections and received clearance Sunday to pass through Turkey’s Bosporus Strait on the way to their final destinations.

The Panama-flagged Navi Star is carrying 33,000 tons of grain to Ireland. The Turkish-flagged Polarnet, which was headed for Turkey, and the Maltese-flagged Rojen, bound for the United Kingdom, carried over 25,000 tons of corn between them.

However, the vessel that left Ukraine last Monday with great fanfare as the first to depart under the grain exports deal had its scheduled arrival in Lebanon delayed Sunday, according to a Lebanese Cabinet minister and the Ukraine Embassy said.

The cause of the delay was not immediately clear and Marine Traffic, which monitors vessel traffic and the locations of ships at sea, showed the Sierra Leone-flagged Razoni at anchor in the Mediterranean Sea near Turkey.

Lebanon’s transportation minister, Ali Hamie, tweeted the ship “that was supposed, according to what was rumored, to reach Tripoli port in Lebanon” changed its status. Hamie refused to comment further when contacted by The Associated Press.

According to Marine Traffic, the ship changed its status Saturday to “order,” meaning it was waiting for someone to buy the cargo – 26,000 tons of corn for chicken feed.

The Joint Coordination Center said three of the carriers cleared to leave Ukraine on Sunday – the Glory, the Star Helena and the Riva Wind, all flagged in the Marshall Islands – were transporting more than 171,000 tons of corn combined. The Glory is destined for Istanbul, the Star Helena to Nantong in China and the Riva Wind to Turkey’s Iskenderun port on the Mediterranean.

The fourth ship cleared for departure, the Liberia-flagged tanker Mustafa Necati is carrying more than 6,600 tons of sunflower oil to Monopoli, Italy.

The center also authorized the first inbound ship under the agreement, saying the Liberia-flagged Osprey S would head Monday to Ukraine’s Chornomorsk port. Marine traffic tracking sites showed the ship north of the Black Sea entrance to the Bosporus, where ships have waited for inspection teams to board.