Chinese Premier Wen Jiabao on Saturday extended condolences to Norweigian Prime Minister Jens Stoltenberg over Friday's deadly attacks in Norway that killed at least 91 people.

In his message, Wen condemned the violent twin attacks, and extended his condolences to the victims and deep sympathy to their families.

At least 84 people were killed when a gunman disguised as a police officer opened fire at a youth camp on Utoeya island, about 40 km west of the capital Oslo.

The shootings occurred hours after a massive explosion ripped through a high-rise building housing the prime minister's office in Oslo, killing seven people.