Iran is now refusing to hand over the black boxes from a Boeing 737 passenger jet that went down in the Islamic Republic, supporting theories that the country was involved in the disaster.

Ali Abedzadeh, the head of Iran’s civil aviation agency, confirmed that the flight recorders would not be handed over to Boeing or the United States, the Persian-language news agency Mehr News reported.

“We will not give the black box to the manufacturer and the Americans,” Abedzadeh announced Wednesday.

The passenger plane, which was carrying 176 people, crashed with no survivors earlier the same day.

The Ukrainian-owned 737 went down shortly after takeoff.

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Without the plane’s black boxes, which record vital information during flight, it might be impossible to confirm what exactly caused the plane to fall from the sky.

Although Iran insists the plane was downed by mechanical issues, the crash came at a time of heightened tension following a U.S. drone strike that killed Iranian Gen. Qassem Soleimani and Iran’s launch of ballistic missiles in response.

Many have speculated that an anti-aircraft gunner with an itchy trigger finger might be behind the deaths.

Video of the crash shows the plane engulfed in flames before finally slamming into the ground.

#Breaking First footage of the Ukrainian airplane while on fire falling near #Tehran pic.twitter.com/kGxnBb7f1q

— Ali Hashem علي هاشم (@alihashem_tv) January 8, 2020

Although it’s unclear what the cause of the plane’s crash was, some speculated that it could be the fault of Iranian air defense systems that may have mistaken a civil aircraft for an American warplane.

The timing of the crash itself is highly suspect. News of the accident broke as the region reeled from a salvo of Iranian missiles fired at two Iraqi airbases known to house U.S. troops.

So far, there have been no confirmed casualties as a result of the missile strikes.

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In an effort to prevent more deaths from any possible misidentification, U.S. civil pilots have been instructed to steer clear of the region.

The Federal Aviation Administration issued a set of flight restrictions aiming to keep civil aviation operators away from the airspace over Iran, Iraq and surrounding areas.

#FAA Statement: #NOTAMs issued outlining flight restrictions that prohibit U.S. civil aviation operators from operating in the airspace over Iraq, Iran, and the waters of the Persian Gulf and the Gulf of Oman. pic.twitter.com/kJEbpPddp3

— The FAA (@FAANews) January 8, 2020

It remains to be seen if the 737 crash was simply caused by a fatal mechanical flaw that came at the wrong time, or was the result of a military blunder.

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