Radio Free Europe quoted an unnamed diplomatic source on Monday who said that Athens is set to lodge a protest with Belgrade for failing to inform it of the weapons being transported by the aircraft that crashed in northern Greece on Saturday.

The Antonov An-12 transport plane registered with the Ukrainian company Meridian Air Cargo was reportedly carrying more than 11 tons of munitions when it crashed in northern Greece, killing all eight of its crew members. The pilot had reported engine problems and was cleared for an emergency landing at the city of Kavala.

According to flight records, the plane was chartered to fly from the southern Serbian city of Nis to Bangladesh, with stops in Jordan and Saudi Arabia – both of which border currently active war zones in Syria and Yemen.

On Sunday, Serbian Defense Minister, Nebojsa Stefanovic, confirmed that the plane was carrying Serbian-made mortar shells, and that it was bound for Bangladesh.

“The ambassador of Greece in Belgrade will lodge a protest saying that Serbia should have informed Greece about the cargo,” Radio Free Europe cited a diplomatic source as saying.

They added that the Greek opposition parties have accused the government of not providing information about the cargo, and have called for an investigation which has been launched in the meantime by state prosecutors.