Kayseri (Turkey): Turkey has said the release of images allegedly showing Turkish spy agency trucks carrying weapons into Syria early last year was an election ploy, with the prime minister denouncing what he called an “illegal action” against Turkey’s interests.

An opposition Turkish daily on Friday published video footage of mortar shells, grenade launchers and tens of thousands of rounds of ammunition stashed under boxes containing antibiotics and marked “fragile”.

Local security forces in January 2014 searched trucks in southern Turkey near the Syrian border on suspicion that they were smuggling arms into Syria and found personnel of the Turkish National Intelligence Organisation (MIT) on board.

Turkey said at the time that the vehicles were on a humanitarian mission to the Turkmen community in Syria.

The new images prompted the opposition to question whether Ankara had provided military support to militants of Daesh fighting in Syria.

In an interview, Prime Minister Ahmet Davutoglu said he could not comment fully because of “state secrecy”, but said Turkey provided the Syrian people and the Free Syrian Army with assistance, without specifying whether the aid was of a military nature.

“I said at the time it was made up of logistical aid directed for the Turkmen community in desperate need of help ... The aid was for the Free Syrian Army and the Syrian people,” he said during a visit to the central Anatolian city of Kayseri.

“The raid on MIT trucks was an illegal action against Turkey’s interests and national security ... And the release of (the video footage) right now is an effort aimed at affecting the elections,” he added.

“But Turkey always does and will continue to do whatever its national security requires, and whatever responsibility it needs to shoulder for humanitarian purposes in the international arena. This is our right. We will not let it be a subject of discussion.”

Tensions are mounting in Turkey ahead of the critical June 7 legislative elections as the ruling Justice and Development Party (AKP) is seeking to maintain the dominance it has enjoyed since coming to power in 2002.

The latest opinion polls indicate its support could fall sharply from the almost 50 per cent of the vote it garnered in 2011 and more than 46 per cent in 2007. Some voter surveys put current support at around 40 per cent.

Turkey has emerged as a key opponent of Syrian President Bashar Al Assad, a one-time ally, calling for his removal from power.

Ankara has vehemently denied arming and supporting the Islamists who are fighting the regime in Damascus as well as a myriad rebel groups.

It allowed Iraqi Peshmerga forces to cross the Turkish border to help defend the Syrian town of Kobani against Daesh insurgents in October.

Davutoglu said that Turkey did not send aid unilaterally to Syria.

“All the assistance is activities carried out together with the international community in the Friends of Syria group ... and not Turkey’s unilateral aid,” he said.

Shortly after the Cumhuriyet’s report, a Turkish prosecutor launched a criminal investigation into whether the daily breached terrorism laws by publishing the footage.

Charges include “obtaining information on state security,” “political and military espionage” and “propaganda for a terrorist organisation”.

The main opposition Republican People’s Party (CHP) said the images were “very disturbing for Turkey’s prestige.”

“Those who illegally sent arms to (Syria) have blood on their hands,” CHP leader Kemal Kilicdaroglu said on Thursday. “Who were those weapons bound for? Were they sent to [Daesh]?” he asked.

The arrests of dozens of soldiers, police and prosecutors over the inspections of the MIT vehicles has sparked widespread controversy, notably after leaked documents circulated on the internet claimed that the seized trucks were delivering weapons to Syrian rebels.

The government has imposed a full-blown media blackout, including on social networks.

Ankara has claimed that the search of the MIT trucks was carried out on the orders of US-based preacher Fathallah Gulen, whom President Recep Tayyip Erdogan accuses of running a parallel state through supporters in the judiciary and police with the aim of usurping his power.