MEXICO CITY (Reuters) - Investigators including U.S. officials began sifting through the wreckage of an Aeromexico-operated passenger jet on Wednesday for clues to what caused it to crash in Mexico’s state of Durango, the head of the country’s civil aviation agency said.

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All 103 passengers and crew survived when the Mexico City-bound Embraer 190 passenger jet smashed into scrubland near the runway during takeoff on Tuesday, evacuating the plane before it caught fire. Nearly everyone on the flight suffered minor injuries, according to Mexican officials.

Sixty-four people have been released from hospitals, Aeromexico said in a Wednesday morning Twitter post. Two people were in critical condition, including the pilot and a minor, the state health department said.

Luis Gerardo Fonseca, director of Mexico’s civil aviation agency, told broadcaster ADN40 that members of his team began working at the site of the crash around 7 a.m. local time (1200 GMT), along with representatives of the U.S. National Transportation Safety Board (NTSB) and the U.S. Federal Aviation Administration (FAA).

Representatives of Embraer SA and the maker of the plane’s engines, General Electric Co, are also assisting, Fonseca said.

Officials said it was too early to say what caused the crash of flight number 2431, but investigators were expected to look into wind shear - a downdraft from storm clouds known as a microburst - as a potential factor.

Although rare, extremely violent and localized gusts can cause problems for even the most modern plane during takeoff and landing, when planes are most vulnerable to sudden weather changes.

Experts say most airline crashes are caused by a combination of human and technical factors. It can take safety investigators months to piece together the complex chain of events leading to an accident.

Determining the cause of the Durango crash may be made easier by the location of the crash, which should allow easy access to evidence, including the two flight recorders, one for cockpit voice recordings and the other for flight data.

Under international rules, Mexico will lead the investigation with support from Brazil, where the Embraer jet was designed and built, and from the United States, where General Electric made the engines.