Two paintings by Pablo Picasso have been stolen from a Swiss exhibition.
Verre et Pichet, Glass and Pitcher, one of the two stolen works
The artworks were stolen on Wednesday after closing time at the show of the artist's work in the small town of Pfaeffikon, near Zurich.
The oil paintings - Head of Horse and Glass and Pitcher - were on loan from the Sprengel Museum in Germany.
Police are examining the theory that the thieves stayed in the building when it shut. They triggered an alarm on leaving at 1900 local time (1800 GMT).
Shortly afterwards, guards noticed that the paintings were missing.
The Sprengel has promised a reward to anyone who has any information that may help recover the paintings.
The value of the works has been put at almost five million Swiss Francs ($4.5m, £2.3m) by the Agence France Presse news agency, quoting Swiss police sources.
The exhibition consists entirely of works on loan and includes 20 original Picasso paintings.