SEOUL, South Korea (AP) — Officials say four South Korean pilots of an Asiana plane that crash-landed in San Francisco this month are being treated for psychological trauma and injuries caused by the incident.

Land, Infrastructure and Transport Ministry officials said Wednesday that the pilots have been hospitalized in South Korea following medical checkups after returning home over the weekend.

The pilots underwent questioning by a U.S. and South Korean joint investigation team while in the U.S. South Korean officials plan to conduct a separate interview with them.

The ministry officials say the interview can start as early as Friday at doctors' recommendation.

The officials gave no further details and spoke on condition of anonymity citing department rules.

The Asiana plane crashed at San Francisco International Airport on July 6, killing three and injuring dozens.