An 108 ambulance vehicle was badly damaged when the oxygen cylinder in it exploded, at Avuku in Kurnool district, on Sunday.
According to police sources, the explosion occurred at Peddammakonda, when the 108 ambulance was heading towards Kunukondla from Avuku in the district to pick up a patient.
The explosion was so powerful that shards of metal and medical equipment on board the ambulance were flung to around 500 metres from the spot.
Initial reports say that there were no casualties.
Preliminary reports suggest that the blast might have occurred after pressure built up in the oxygen cylinder. The movement of the ambulance over the rural roads might have built up the pressure, according to the police.
Police officials are, however, trying to ascertain the exact reasons behind the explosion.
The officials said that even heat could have triggered off the explosion.