Four paintings by Pablo Picasso worth an estimated $30 million were stolen Monday by thieves who broke into Czechoslovakia's national gallery.

They forced their way into the gallery housed in Prague's Sternberg Palace in the early hours, dodging several alarm systems, gallery director Lubomir Slavicek said.The four paintings stolen were "Absinthe and Playing Card," "Mandolin and Glass of Pernod," "Table with Goblet" and "Port of Tadaques."