MOSCOW 

One of three armed men was killed when they tried to enter Russia from neighboring Ukraine on Friday, the Russian Federal Security Service (FSB) said.

The incident took place on the border between Ukraine and Russia's Belgorod region, the FSB said in a statement.

According to the FSB, border guards tried to arrest the men, but they faced armed resistance.

"As a result of return fire, one of them was critically injured, and the two others fled back to Ukrainian territory," it said.

Belgorod is near areas of Ukraine claimed by Russian-backed separatists.

In 2017, a similar incident occurred in Russia's Kursk region, when Russian border guards found a group of unknown people who tried to cross the border outside the checkpoint.

When border guards tried to check their documents, a firefight ensued, resulting in the death of one guard and one in the group trying to cross.