Indonesias transport ministry will launch an investigation after two Batik Air pilots fell asleep during a recent flight, according to state news agency Antara, citing the ministrys civil aviation director-general M Kristi Endah Murni.

According to a preliminary report released Saturday by the National Transportation Safety Committee (KNKT), both the pilot and co-pilot fell asleep simultaneously for 28 minutes during a flight from Kendari in Southeast Sulawesi province to the capital Jakarta on January 25, causing navigational errors as the aircraft was not in the correct flight path.

None on board - including 153 passengers and four flight attendants - were injured during the flight, and there was no damage to the aircraft, the KNKT preliminary report said.

The flight, BTK6723, lasted two hours and 35 minutes, and successfully landed in Jakarta, according to Antara and the preliminary report.

CNN has reached out to Batik Air.

According to the report, the second-in-command pilot had notified his co-pilot earlier in the day that he had not had proper rest.

In the flight before the incident, the second-in-command was able to sleep for about 30 minutes. After the aircraft departed Kendari and reached cruising altitude, the pilot-in-command asked for permission to also rest and the second-in-command took over the aircraft. Around 90 minutes into the flight, the second-in-command then inadvertently fell asleep, according to the report.

Twelve minutes after the last recorded transmission by the co-pilot, the Jakarta area control center (ACC) tried to reach the aircraft, but there was no reply from the pilots, it said. Around 28 minutes after the last recorded transmission, the pilot-in-command woke up and realized the plane was not in the correct flight path. At that point, he woke up the second-in-command and responded to the ACC, it said.

The preliminary report detailed that the pilot-in-command told the ACC that the flight had experienced a radio communication problem that had been resolved.

The report did not reveal the names of the pilots, but identified the pilot-in-command as a 32-year-old Indonesian male and the second-in-command as a 28-year-old Indonesian male. The second-in-command had one-month-old twins and had to wake up several times to help his wife take care of the babies, the report said.

We will conduct an investigation and review of the night flight operation in Indonesia regarding the Fatigue Risk Management for Batik Air and other flight operators, Murni said in a statement, according to Antara.

Flight crews of BTK6723 have also been grounded according to standard operating procedure pending further investigation, she added, according to the news agency.

She also said the agency will dispatch a flight inspector authorized on Resolution of Safety Issue (RSI) to investigate the cause of the incident and recommend mitigation measures to flight operators and supervisors, Antara reported. (CNN)

A Batik Air passenger plane at Sultan Iskandar Muda International Airport in Indonesia in 2022. Chaideer Mahyuddin/AFP/Getty Images