Who were those three US citizens who crashed in Yerevan?

On April 6 mass media spread information about the car crash which happened in Yerevan, on Tumanyan street, near SAS supermarket. According to the information, Mercedes car without numbers hit three foot-passengers. Later photo journalist Gagik Shamshyan informed that the driver of the car was Yerevan resident Ashot Gevorgyan, and the victims were Cameron Georgine, Liem Zaajeri and Zakari Goldariani. The latters are the US citizens and work in the US peace corpus as volunteers. They were wounded and were taken to the First hospital. 34 year-old Albert Stepanian who was in Mercedes, was also taken to the hospital as a result of the crash.
As Times.am managed to find out A. Stepanyan suffered from the crash most of all and he is under doctors' supervision till now. And those three US citizens who also were wounded are not in Armenia any more. According to our information, the fellow-workers of the US Embassy in Yerevan organized their treatment in abroad. The US diplomats even did not let the doctors give them the needle of medicine to reduce their pain without the diplomats' presence. According to our information the above noted US citizens were taken to Turkey on April 7 with charter flight.
During the conversation with Times.am head of the press service of the Zvartnots International Airport Gevorg Abrahamyan confirmed that three charter flights were taken in Zvartnots Airport on April 7.
And now here is a question: who were and which mission had those three US citizens who crashed on Tumanyan street and whose treatment was not trusted to the Armenian doctors and for whom US diplomats took separate charter flights?