“Given certain activities and recent insecurities in Eastern Turkey, the foreign ministry advises Iranian citizens who are going to head for Turkey to avoid ground routes until further notice,” the foreign ministry said in a statement.

It further called on Iranian nationals to “opt for the air route to travel to the country (Turkey) as long as possible.”

The statement came after a Friday attack by unknown gunmen on a bus carrying Iranian tourists in eastern Turkey killed one and injured three others.

A week earlier, two Tehran-Ankara passenger trains were attacked in Eastern Turkey.

The services, which run between Iran and Turkey, were hit by blasts from remotely detonated landmines, in attacks Turkish officials blamed on Kurdistan Workers’ Party (PKK) militants.

Following the attacks Iran cancelled all trains to the Turkish capital.

Iran’s Rail Transportation Company (Raja) announced in a statement at the time that it cancelled its train services to the neighboring country for security reasons.