German investigators have found a third drone and a substance suspected to be the military explosive hexogen in the area around Leipzig/Halle Airport, according to German public broadcasters WDR and NDR and the Süddeutsche Zeitung, citing Reuters.

The drone was discovered on August 14, 10 days after an earlier incident at the airport. Investigators also found around 50 grams of a substance they believe to be hexogen, according to media reports. German prosecutors had not immediately commented on the findings.

The discovery adds to an investigation into a suspected attempted attack at the airport. On August 4, a drone carrying explosives was found near a Ukrainian Antonov transport aircraft used to deliver military supplies.

Investigators also suspect that a second drone may have crashed into a DHL cargo aircraft shortly after the airport was temporarily closed following the initial discovery.

The reports cited sources who suspect that Russian military intelligence may have been involved in the attempted attack. Moscow has denied the accusation.