People in the southeastern city of Mariupol woke to the sound of explosions on Thursday and some started packing bags to leave after Russia invaded Ukraine.
Mariupol, eastern Ukraine's main port, was not attacked as the invasion began. But residents fear it could become a target for Russia as it is strategically important and only about 10 kilometres from areas controlled by pro-Russian separatists.
Despite blasts from the direction of its easternmost suburbs, some people tried at first to stick to their daily routine. Mariupol's steel mills - important for Ukrainian exports - opened, and anglers sat along the Kalmius River that runs through the city of about half a million.
But it became clear that many shops were not opening and some people packed their belongings into cars to flee the city.
"We are going into hiding," said one middle-aged woman.
Another resident, 17-year-old Yulia, said via the messaging app Telegram: "We have a shelter in our house but I don't know whether it's big enough and whether it is that safe."
Pro-Russian separatists did not attack Mariupol when they seized swathes of eastern Ukraine in a conflict that began in 2014.
Capturing it now would let Moscow link Russian-controlled Crimea over land to the separatist enclaves and secure complete control over the coast of the Sea of Azov, increasing economic pressure on Ukraine's government.
A 19-year-old woman in Mariupol who gave her name only as Ira said that after the morning explosions it was "quiet for the present. All (electronic) communications are working."
West of the city, Reuters witnesses saw a cloud of smoke billowing from a fire in a military installation.
A Ukrainian armoured column thundered along a road outside Mariupol. Soldiers on tanks showed victory signs to passing cars which honked their horns in support.
Further along the road, in the towns of Mangush and Berdyansk by the Sea of Azov, cars queued at petrol stations, and people stood in line at cash machines.
Ukrainian missile launchers could be seen beside roads in the area.
