A robber bored a hole through the wall of a jewelry shop and walked off with about 200 luxury watches worth $3.2 million in Tokyo's upscale Ginza district, police said Saturday.

Investigators discovered a 16 to 20 inch hole in one of the store's walls, said Shinya Watanabe, a spokesman for the Tokyo Metropolitan Police.

Last February, $540,000 in jewelry was stolen from another Ginza store through a hole in a concrete wall. Police said it was not clear whether the two thefts were linked, or if the thief entered the store to remove the watches.

A security guard monitoring the store Friday afternoon did not notice anything unusual, Watanabe said. Police had no witnesses but were interviewing employees at neighboring stores for possible leads.

"Whoever did this bored a hole into a concrete wall," Watanabe said. "The noise must have been quite loud."

The store, Tenshodo, is located in the heart of Ginza, the busiest high-end shopping district in Tokyo. It was founded in 1879 and sells jewelry and luxury watches such as Rolex, Chopard and Piaget.

Saturday was the start of the New Year sale season, when bargain hunters flock to department stores and shops offering big discounts. A block from Tenshodo, customers lined up at Mitsukoshi department store waiting for its 10 a.m. opening.