Burglars have stolen three diamond jewellery sets from one of Europe's largest treasure collections - the Dresden green vault in eastern Germany.

The sets consist of 37 parts each, and the thieves may try to break them up.

Dresden police and museum officials say they are still trying to establish exactly how much was stolen in the break-in early Monday.

Saxony's ruler, August the Strong, created the collection in the 18th century.

The 18th-century sets are reported to also include some rubies, emeralds and sapphires.

Dozens of police cars are at the scene and the green vault is now shut. The thieves - still on the run - got in by removing part of an iron grille on a ground-floor window, then smashing the glass.

Ms Ackermann described the jewels as "priceless - we can't put a figure on it".

Earlier, the popular German Daily Bild said the thieves had grabbed jewels worth one billion Euros.