Armed and unmasked thieves stole two Pablo Picasso prints and two works by Brazilian artists from Sao Paulo’s Pinacoteca Museum on Thursday, officials said, according to Reuters.

It appears this is the second major art theft in the Brazilian city in six months.

Three robbers entered the museum and threatened security guards. They escaped with the Picasso’s 1963 print “The Painter and the Model” and “Minotaur, Drinker and Women” from 1933, the same source reports.

The pieces were taken out of the museum in two bags. The institution has no metal detectors.

The thieves also took the print “Couple" by Brazilian artist Lasar Segall (1891-1957) and the painting “Women in a Window” by fellow Brazilian Emiliano Di Cavalcanti (1897-1976).

The artworks, belonging to the Jose and Paulina Nemirovsky Foundation, worth in total about 1 million reais ($613,000).

Police delegates Gaetano Del Vegine, Youssef Abul Chaina and Secretary of Culture João Saad held a news conference where they presented the sketches police made of the thieves who stole the four paintings, Art Daily reports.

In December, another Picasso painting, “Portrait of Suzanne Bloch” was stolen from the Sao Paulo Museum of Art along with Brazilian painter Candido Portinari’s “The Coffee Worker.” Both were recovered unharmed, within a couple of weeks later.