The explosion that rocked an Iranian port had its epicenter at a facility ultimately owned by a charitable foundation overseen by Supreme Leader Ayatollah Ali Khamenei’s office.

A massive explosion and fire that rocked a port Saturday in southern Iran, purportedly linked to a shipment of a chemical ingredient used to make missile propellant, has killed at least 40 people and injured around 1,000 others, officials said.

Iranian officials ruled out sabotage as being behind the recent fire at the Shahid Rajaee port but have not commented on the cause of Tuesday’s blast in Isfahan.