Emirati investigators said Sunday there is no evidence a UPS cargo plane that crashed in Dubai in September was brought down by an explosion, heading off speculation that the accident might be linked to parcel bombs sent from Yemen.
U.S. President Barack Obama's counterterrorism adviser has said American investigators involved in the probe are taking a closer look at the crash in the wake of last week's bomb plot.
Questions about the fate of the three-year-old Boeing 747-400 resurfaced following the discovery of two parcel bombs sent through international shipping companies at airports in Dubai and Britain. Authorities say that plot bears the hallmarks of al-Qaida's Yemeni offshoot.
The UAE's General Civil Aviation Authority said in a statement sent to the state news agency WAM on Sunday that the wreckage and flight recorders of the UPS cargo plane that crashed Sept. 3 showed no indication of an onboard blast.
"The GCAA investigation team has thoroughly analyzed the technical data and has concluded that there was no presence of acoustic evidence or any forensic indication supporting the detonation of an explosive device," the Emirati regulator said.
A fire onboard the plane prompted the pilots to turn back to Dubai shortly after takeoff. Emirati investigators say the two-man crew struggled with visibility and communication problems as the cockpit filled with smoke.
The cause of the fire is unknown. Both pilots died when the plane crashed into a military base after attempting to make an emergency landing.
U.S. deputy national security adviser John Brennan told CNN's "State of the Union" in an interview aired Sunday that counterterrorism analysts are working with the National Transportation Safety Board to understand the cause of the crash.
"The crash of the one plane off of Dubai, we are looking very carefully at that," Brennan said. "We're making sure that we look at possible other events or other developments that might have some relationship with the most recent packages that we have discovered."
The Emirates is leading the probe with help from U.S. and the plane's manufacturer Boeing Co.