Shaken but relieved airline passengers were tonight continuing their journeys after surviving a terrifying ordeal in which a gaping hole appeared in their jumbo jet 30,000ft up.

Flooring gave way, part of the ceiling collapsed and debris flew into the first class cabin on the Qantas Boeing 747 which was flying from London to Melbourne.

Scared passengers, some of whom were woken up by a loud bang, had to don oxygen masks as the plane descended after losing cabin pressure on the Hong Kong-Melbourne leg of the flight today.

Film shot by passengers and displayed on websites showed the scenes on board the plane as the captain announced that he was making for Manila in the Philippines for an emergency landing.

Passengers spoke of "part of the ceiling" flying past them, while others told how children were crying. Some aboard vomited after the plane managed to land safely at Manila, with all 346 passengers and 19 crew able to disembark normally.

On film, applause for the crew from the passengers as the plane touched down could clearly be heard.

As air accident investigators probed the cause of the incident, passengers, who spent Thursday night in Manila, were flying on to Melbourne in a replacement Qantas Boeing 747.

Initial investigations suggested that a section of fuselage had separated and that there had been an "explosive decompression".

Pictures of the stricken plane at Manila showed a large hole in the aircraft's fuselage through which luggage could be seen.

Debra Manchester, a housewife from Buckinghamshire, was sitting in first class when the incident began.

She told The Times Online: "Newspapers and what looked like part of the ceiling flew past me. We didn't know what was happening to the plane. After a while, things calmed down and there was a deadly silence.

"There was still debris all around our feet but we all started to feel a bit safer when we could take our masks off."

Mrs Manchester said luggage was "hanging out" of the hole where the hold had been, and the emergency door above appeared to have come loose.

She claimed that 20 minutes after the plane first took off from Heathrow, she heard a loud bang near one of the doors.

"You have to wonder if that explosion could have caused the second one," she said.

Phil Restall, from London, said he was woken "with a jolt" by the loud bang before the plane descended rapidly.

He told the BBC News website: "No-one panicked, there was no screaming. It wasn't your typical television movie. Everyone listened to the cabin staff."

He said other passengers had told him young children in the main cabin were crying.

Mr Restall, who was reassured to see the engines "still spinning", said they wore the oxygen masks for about 15 minutes, until the plane levelled out.

The pilot then told passengers they were going to land in Manila to have a look at the damage.

Mr Restall went on: "Everyone was fairly calm, partly because they didn't realise the extent of it. After we disembarked it started to dawn on people that this was a major incident. There were 350 people up there who were very lucky.

"Seeing the hole caused a lot of emotion. People were physically shaking. Many realised how close they were to their own mortality."

Robin McGeechan, 42, from the Midlands, said he heard a loud bang after the aircraft had taken off from Hong Kong.

He went on: "Incredibly there wasn't much panic on board, but obviously a lot of people were pretty scared. We were told by the crew that a door had popped but that obviously wasn't the case.

"We only realised what the true situation was when we saw the great big hole after the plane landed."

Manila airport spokesman Octavio Lina said: "There is a big hole in the belly of the aircraft near the right wing, about three metres in diameter.

"Upon disembarkation, there were some passengers who vomited. You can see in their faces that they were really scared."

Qantas chief executive Geoff Dixon said: "All 346 passengers and 19 crew disembarked normally and there were no reports of any injuries to passengers or crew."

He added that the flight crew performed emergency procedures after oxygen masks were deployed. Initial inspections revealed the aircraft sustained a hole in its fuselage, and it was being inspected by engineers.

Praising the crew, he said: "This was a highly unusual situation and our crew responded with the professionalism that Qantas is known for."