Spain's King Juan Carlos is undergoing lung surgery to remove a growth, the royal palace said today.

The palace said the 72-year-old king was being operated on in Barcelona.

A statement issued by the palace medical team said doctors carrying out a routine check-up last month found what was described as "calcification" in the king's right lung. After further tests they decided to operate today. Doctors will be carrying out tests on the growth after they have removed it. The royal palace declined to say if the growth was cancerous.