An Iranian aerospace engineer said to have worked on developing missiles and drones at a research and development center in the central city of Yazd has died under suspicious circumstances. 

Ayoob Entezari, who held a PhD in Mechanical and Aerospace Engineering from Tehran’s Sharif University, died last week with some reports mentioning food poisoning as the cause of his death, Iranian and Israeli media reported on Saturday. He reportedly took part in several projects at the Yazd Institute of Technology.

The circumstances surrounding his death are shady as some people on social media say the Iranian scientist was killed and Mossad is also mentioned in some reports as being responsible but no official source has yet spoken out about his death.

The reports came a day after Iran confirmed the death of another colonel from the Quds Force, Ali Esmailzadeh of the Islamic Revolutionary Guard Corps, the second in two weeks from the unit which allegedly oversees terror operation abroad.

Iranian government and IRGC media said that Col. Esmailzadeh died “in an incident in recent days” at his home without mentioning any details after Iran International quoted sources in Iran as saying that the IRGC killed him over suspicions of espionage. Officials of the Revolutionary Guard told Esmailzadeh’s family that the reason for his death was suicide.

He was a close colleague of Colonel Hassan Sayyad-Khodaei, the acting commander of the elite Qods Unit 840, who was earlier shot dead behind the wheel of his car outside his home in Tehran on May 22 by two gunmen who fled the scene on a motorbike.