With Ukraine already reeling from Russian attacks across the country, reports suggest that an “amphibious assault” is underway near the city Mariupol, located on the north coast of the Sea of Azov.

Russia is “putting potentially thousands of naval infantry ashore there,” reported CNN citing an unnamed US defence official, who went on to say,” the general assumption is they are going to move towards the northeast, towards Mariupol and the Donbas region.”

Also read | Russia bans British Airways from airspace, after UK acts against Russian carrier

The report of the new amphibious assault comes hours after Turkey refused Ukraine’s request to stop the passage of Russian warships through straits under Turkish control.

CNN also cited a senior US official and reported that over 200 missile strikes had taken place across Ukraine since the Russian invasion began on Thursday morning.

Also read | ‘We are defending our country alone,’ Ukraine’s Volodymyr Zelensky requests solidarity

The official further told the media outlet that Russia had “about a third” of the combat power they had assembled for the invasion in Ukraine, suggesting that further deployments may come.

“That does not mean that they will not commit more. I’m just giving you a snapshot of what we’re seeing right now,” the official added.

Also read | Watch | Russian tanks seen entering Ukraine capital city Kyiv

Despite not having all forces in place, Russia’s campaign in Ukraine has largely been successful thus far: Moscow has said that it has destroyed more than 74 military installations, and Russian forces have reached the Ukrainian capital, Kyiv, less than 48 hours since marching into Ukrainian soil.

The invasion has also precipitated a refugee crisis. Since the invasion began, around 50,000 Ukrainians have fled the country in search of safe refuge according to United Nations High Commissioner for Refugees Filippo Grandi.