The Ukrainian marine unit commander in city of Mariupol, currently under siege by Russian forces, has penned a letter to Pope Francis in which he urges the religious leader to help save those still in the city, CNN reports, per online newspaper Ukrainska Pravda.

Maj. Serhi Volyna, commander of the 36th Separate Marine Brigade, began his letter to the Pope by noting he is Orthodox, not Catholic, but “I believe in God and I know that light always overcomes darkness.”

“I have not seen your appeals to the world and I have not read all your recent statements; I have been fighting for more than 50 days, completely surrounded, and all I have time for is a fierce battle for every meter of this city that is surrounded by the enemy.” Volyna continued, per the text of the letter as published by Ukrainska Pravda.

“You have probably seen a lot in your life. But I am sure that you have never seen the things that are happening to Mariupol. Because this is what hell on earth looks like.”

“I am turning to you for help,” the commander pleaded. “Because the time has come when prayers are not enough. Help save them.”

Read more at CNN and Ukrainska Pravda.