The Port city of Mariupol
A Ukranian serviceman walks on a beach in the port city of Mariupol on the Azov Sea, March 20, 2015. Reuters/Marko Djurica

Just 1 mile from the Sea of Azov in southern Ukraine, a small village has become the most recent symbolic staging point where Ukrainian and pro-Russian forces are continuing to defy a delicate ceasefire. While the village of Shyrokyne has little strategic value, it has been described as a final buffer zone between separatist forces and the port city of Mariupol, where a flare-up in hostilities could reignite the conflict.

After gaining its first access to Shyrokyne on Sunday, the Organization for Security and Cooperation in Europe (OSCE), the group charged with overseeing the ceasefire, said that 60 percent of the area had been destroyed, calling the scenes “catastrophic” in a report.

“I am profoundly disappointed that, in the face of mounting deaths and injuries among the civilian population, the calm that prevailed in Shyrokyne for two days has not endured,” Ertuğrul Apakan, chief monitor of the OSCE special monitoring mission to Ukraine, said. “I urge all sides to silence their guns immediately, and to allow the residents of Shyrokyne to return to their homes and to a peaceful existence.”

Shyrokyne, which lies just 22 miles from the Russian border and 13 miles from the port city of Mariupol, has endured constant shelling over the past few weeks, despite the ceasefire officially in place since Feb. 15.

Ukrainian army officials say that the ceasefire has defused most of the conflict around the contested regions of Luhansk and Donetsk in east Ukraine, but also say that the window of relative peace created by February's Minsk II agreement is being used by the rebels to prepare for a new offensive on Mariupol. Given that imminent risk, many have left the east side of the city, which is the side closest to the rebels.

Many in Mariupol say that the pro-Russian rebels, working with the Donetsk People’s Republic, want to create a land bridge from the Russian border to the Crimean peninsula, which was annexed by Russia in March 2014.

According to Steven Pifer, former U.S. ambassador to Ukraine between 1998 and 2000, the city must be a “tempting” target for rebel forces.

“If they do not intend to implement Minsk II, seizing Mariupol would be an important step to make a frozen separatist-occupied Donbass economically viable," Pifer said in a Brookings report from Mar. 20. “Mariupol is the port through which much of the steel and other industrial products of the Donbass are exported.”

Ukraine is in dire financial straits. The loss of one of the country’s key industrial cities would deal a further blow on top of losing another battle against the rebels.

The broader political and military aspects of an attack on Mariupol would be catastrophic. Pifer points to what would be “horrific” street fighting in the city if rebels made it inside as well as the total breakdown of the Minsk II agreement from both sides. And with the ceasefire utterly broken, U.S. President Barack Obama would no longer need to hold off on sending weapons to Ukraine in order to give the Minsk agreement a chance. Russia would also likely face new and tougher sanctions, Pifer said.

The Ukrainian military has begun establishing bunkers, trenches and strategic fighting positions in the hills above Mariupol and in the city.

“The rebels are all saying that Mariupol is an important strategic place -- politically important, too," a commander with the 37th Tank Battalion told Voice of America. "But considering our forces and troops, it will be difficult, very difficult for them. Everyone is ready.”