A media freedom watchdog has called on Turkey's president to stop "bullying" journalists after he accused a newspaper editor of espionage and threatened punishment for publishing images of what the paper said were Turkish trucks carrying ammunition to Syrian militants.

In a statement late Monday, the Committee to Protect Journalists condemned President Recep Tayyip Erdogan for threatening legal action against the Cumhuriyet newspaper editor Can Dundar.

Last week, the paper published images from January 2014 when local authorities searched Syria-bound trucks, touching off a standoff with Turkish intelligence officials. Cumhuriyet said the images were proof that Turkey was smuggling arms to rebels — a claim the government rejects.

The CPJ said: "We call on (Erdogan) to stop bullying journalists ... just because he doesn't like what they report."