The bodies of 30 AirAsia crash victims have been recovered from the sea as rescuers continue to scour the seabed for wreckage.

Some of the bodies were discovered still strapped into their aircraft seats, according to officials involved in the search.

Among the recovered victims were two children, according to reports. So far, only four have been identified and their bodies returned to their families.

There are now 65 ships, 14 planes and 19 helicopters involved in the search and rescue mission, six days after flight QZ8501 disappeared from radar screens over the Java Sea with 162 people on board.

The commander of one of the Indonesian naval ships involved in the search said the tail of the plane had been sighted at a depth of 29m.

The Singaporean defence minister Ng Eng Hen posted pictures of window panels recovered from the sea on his Facebook page on Friday morning.

He wrote: “RSS Supreme recovered a piece of an aircraft this morning, likely to be a window panel. They have informed the Indonesian search authorities and will be handing over the item.”

Sonar equipment and metal detectors are being used to try to discover the black box, which will help investigators establish what caused the plane to smash into the sea.

Bad weather is known to have contributed to the disaster, which came half way through a short haul flight from Surabaya in Indonesia to Singapore.

The pilot had asked air traffic control for permission to climb the Airbus A320 to a higher altitude to avoid storm clouds but heavy air traffic meant this request was denied.

Indonesia’s Search and Rescue Agency chief Henry Bambang Soelistyo said: “We will focus on underwater detection.”

The black box data recorder contains crucial information such as engine temperature, vertical and horizontal speed.

The search team is also hunting for the voice recorder, which will have captured conversations between the pilot and others in the cockpit.

Mr Soelistyo estimated the fuselage would be lying at a depth of between 25m and 30m (80ft-100ft).

The victims identified and returned to their families are Hayati Lutfiah Hamid, flight attendant Khairunisa Haidar Fauzi and passengers Kevin Alexander Soetjipto and Grayson Herbert Linaksita.