The new charge against Anders Behring Breivik would mean he could serve more than the current 21 years he faces for terrorism-related charges after Friday's twin bombing and shooting, a term that many Norwegians feel is not long enough.

Prosecutor Christian Hatlo told Tuesday's Aftenposten newspaper that the new charge, which became possible after entering into law in 2008, was currently only "a possibility".

"Police have so far cited the law on terrorism but seeking other charges has not been excluded," police spokesman Sturla Henreiksboe told AFP.

"No final decision has yet been taken," he said.

Copyright AFP (Agence France-Presse), 2011