Spain's King Juan Carlos has come under intense media fire for hunting elephants in Botswana when his country was being sucked back into the eurozone's financial crisis and one young Spaniard out of two was unemployed.

Spanish media on Sunday pointed to the cost of his trip and criticised the lack of transparency of the Royal Household, three months after it promised to disclose its income following a corruption probe linked to the king's son-in-law.

The royal holiday last week would have remained secret if the king had not tripped on a step, fractured his hip and had to be flown back urgently to Madrid to undergo hip replacement surgery on Saturday morning.

"Awful. I think what the king did is awful," said Angelica Diaz, a 70-year-old Madrid resident. "Because of the lack of solidarity with people here who are going hungry. What he did is wrong. He has to show more humanity."

Interest rates for Spanish bonds have risen alarmingly in recent days, with fears mounting that the country could be the next in Europe to need a bailout. Spain is also struggling with 23 per cent unemployment - the highest in the 17-nation eurozone - which soars to nearly 50 per cent for young workers.

Juan Carlos called on Spanish leaders in his annual Christmas message to set a good example and, more recently, he said there were times when he could not sleep because of concern about Spain's youth unemployment problem.

Last week he cancelled his regular weekly meeting with Prime Minister Mariano Rajoy because he had already left for Botswana, several newspapers said.

"It was an irresponsible trip, taken at the worst possible moment," the daily El Mundo said in an editorial. "The image of a monarch hunting elephants in Africa at a time when the economic crisis in our country creates so many problems for the Spanish people is a very poor example."

Juan Carlos should "admit his mistake and learn from what happened," the paper said.

Juan Carlos' family has also been in the news lately.

The king's son-in-law Inaki Urdangarin is a suspect in a corruption case, accused of using his position to embezzle several million euros in public contracts through a not-for-profit foundation he ran.

Over Easter, the king's 13-year-old grandson shot himself in the foot with a shotgun, even though by law in Spain you must be 14 to handle a gun. The boy's father could face a fine.

News of the king's latest trip came at a time when Spain's  political leaders face growing social anger.

Support for Rajoy fell sharply in April after his government announced deep spending cuts and health and education reforms to fight the sovereign debt crisis, an opinion poll showed on Sunday.

Rajoy, who visited the king on Sunday, said he would resume his duties gradually and would attend their weekly meeting next Friday.