By Madrid correspondent Daniel Schweimler

The opera-goers of Madrid have a reputation for being tough critics, but there has rarely been anything like the near-riot at the city's Teatro Real opera house on Friday evening.

Respectable women in fur coats screamed and shouted while men in tuxedos angrily waved their programmes.

The Spanish Secretary of State for Culture was forced to hide in a lift - he is said to be still shaking - and staff say there was some damage done to the theatre doors.

It all happened at what was supposed to be a respectful tribute to the much-loved Spanish tenor, Alfredo Kraus, who died last year.

Firstly, the concert started half-an-hour late. Then the full house, which had paid up to a $100 a ticket, was told that one of the singers, Maria Bayo, was sick and would not appear.

It was quickly followed by a second announcement - that another name on the programme, Ramon Vargas, had suffered a family tragedy and would not make it.

Final straw

Programmes were ruffled; the agitated murmuring began.

But then came the final straw: the audience was told that the top billing, the Italian tenor Luciano Pavarotti, was indisposed and had not even made the journey to Madrid.

The audience booed and whistled. Many of them stormed out. "Scandalous!" they screamed. "Cancel the concert!" shouted others. "Kraus never deserved this!"

Several gathered in the main reception area to demand explanations.

Culture Secretary Miguel Angel Cortes was spotted and had to take refuge in a lift to escape the angry crowd.

When the concert did get under way the first singer was booed off the stage and opera house director Juan Cambreleng was forced to appeal for calm.

He called the audience's behaviour "irrational" and said he was disgusted to find that damage had been done to some of the theatre's doors.

"With the flu this sort of thing is normal," said Mr Cambreleng explaining why Maria Bayo wasn't there.

Referring to Mr Pavarotti he said "Pavarotti had a plane to come this afternoon and then he rang me that he was unable to come."

But Mr Cambreleng has promised refunds to any angry opera fan who demands it.

Echoes of Marx

The Spanish newspaper El Pais, likened the scenes to something from the Marx Brothers film "A Night at the Opera".

It said the audience in their fur coats and ties behaved like some of the more violent Real Madrid football fans.

The concert did finally go ahead, with a series of arias conducted by Placido Domingo and Enrique Garcia Asensio, watched by Alfredo Kraus's family, the prime minister's wife and other invited dignitaries.

But the scandal was not over yet.

At the end of the evening, the opera house management announced that the event had been a great success.

Alfredo Kraus will be choking in his grave.