THESSALONIKI, Greece  — A Greek border guard was shot in the abdomen Saturday while patrolling an area of the Greek-Turkish border where undocumented migrants seek to enter the European Union, Greek police said. The injuries are not life-threatening.

Four Greek border guard officers were on duty along the Evros River, the land border with Turkey, shortly after 6 p.m. Saturday, when three or four shots rang out from the Turkish side, police said.

A bullet hit one of the border guards in the lower abdomen. The injured man was taken to a hospital in the town of Didymoteicho, where he was operated on, police said.

Police added that the injured officer was in stable, non-life-threatening condition.

Greek media reported that police officials believe the shooter or shooters were probably human traffickers. Officials are not allowed to speak about cases under investigation and the officials requested anonymity.

A police statement said the bullet was fired from a pistol.

The patrolling officers had detected some movement on the Turkish side, but could not tell how many people were there because their view was blocked by thick vegetation. With several more border guards converging on the site, no crossing was made.

The border guards are a special unit of Greece’s police.