New Delhi, June 4 (IANS): A massive search operation using satellites of Indian Space Research Organization (ISRO), sorties by navy's long range maritime reconnaissance aircraft P8I and helicopters equipped with advanced sensors over the possible crash sites has not provided any clues about the wreckage of the missing Indian Air Force's AN-32 transporter in Arunachal Pradesh, giving anxious moments to the families of 13 persons on board, including six officers and seven others.

The rescuers have not picked up signals from the emergency locator beacon fitted in the cargo compartment of the aircraft as every hour is proving to be agonizing for the families who are being regularly informed about the search efforts.

An IAF statement said ISRO's CARTOSAT and RISAT satellites are taking images of the area and helicopters and aircraft fitted with advanced sensors were deployed. The search by helicopters was called off after sunset but sensors with night capability and the ground searches will continue the search operations. The sweeps by synthetic aperture radars on C-130 Super Hercules has also not given any indication abut the wreckage.

As the search continues, IAF's ageing fleet of transport aircraft has come under lens as the upgradation of 100 odd Soviet-era AN-32s have gone about at tardy pace. India had signed a contract with Ukraine for upgrading these aircraft after the 2009 in the same area of Arunachal Pradesh but only around half of the fleet has undergone transformation and the new inductions have also been delayed.

The latest incident comes after the IAF lost an AN-32 in Bay of Bengal when the flight from Chennai to Port Blair went missing with 29 onboard was never found.