Greece has recovered works of art by Pablo Picasso and Piet Mondrian, stolen from its National Gallery in 2012, authorities said on Tuesday.

Thieves broke into the gallery and snatched Picasso's 1939 painting "Woman's Head", donated by the Spanish artist in 1949, and Dutch painter Mondrian's "Mill" dated 1905.

To mislead the guard, the thieves had activated the gallery's alarm system several times before breaking into the building early in the morning. The guard turned off the alarm only to spot one of the thieves through the motion detector.

On Monday, authorities arrested a 49-year-old Greek man who confessed that he had stolen the paintings and led police to a forest outside Athens where he had hidden them, the Citizens' Protection Ministry said on Tuesday.

Footage handed out by police from the site showed one of the paintings sealed in a package under bushes.

The arrested man said a sketch by Italian painter Guglielmo Caccia, donated to the gallery in 1907 and also stolen in 2012, had been destroyed, the ministry said.

The paintings will be exhibited once again in the National Gallery, which opened in March after nine years of renovation work, as part of celebrations marking the 200th anniversary of the Greek War of Independence in Athens.

-In our new gallery, they will find the place they deserve- Citizens' Protection Minister Michalis Chrisochoidis told a joint news conference with Culture Minister Lina Mendoni.

-Picasso dedicated the painting to the Greek people- he said. -There was a Greek man who took it away. There were Greeks who brought it back.-

Mendoni said the Picasso painting bore an inscription from the painter to the Greek people for their fight against fascism.

-That is the reason why it was impossible for the painting not only to be sold but also to be exhibited anywhere- she said.