Police arrested two men and were hunting for a third after armed robbers held up a Cartier jewellery in a central square in Monaco on Saturday.
Police ordered shoppers to take refuge in nearby stores and cafés as they set up a huge security perimeter around the store in the Place du Casino on the heart of the Mediterranean principality.
Dramatic video footage circulated on Twitter reportedly showing heavily-armed officers scouring a building site where one of the robbers was believed to be hiding.
Gunfire was heard around the time of the robbery, although it was not immediately clear if the shots were fired by police or by the robbers.
Three masked men burst into the upmarket jewellery store mid-afternoon on Saturday and then made off with an as yet undisclosed amount of goods.
Police intercepted one of the men and recovered part of the loot as the thieves made their escape but two others managed to flee, Monaco officials said.
A car was set on fire in a tunnel not far from the scene of the crime, but police could not confirm that it was a getaway vehicle that the robbers had burned to destroy evidence.
A Cartier store in nearby Cannes was held up two years ago as the town’s famous film festival got under way. The stolen goods were worth an estimated €17 million.