Spread across two buildings, the Picassos were etched in 1958. They are the first Picassos in concrete and four of them were especially designed for the site.
Norway is debating what to do with the damaged buildings after eight people were killed in the bombing.
The new government is expected to consider the issue next spring and government officials insist no decision has been made.
"This is a highly emotional debate," Paal Weiby, a spokesman for government's property manager Statsbygg, said.
"A lot of people would be terrified to go back."