Powerful explosions shook central Oslo on Friday afternoon, blowing out the windows of several government buildings, including one housing the office of the Norwegian Prime Minister.

(An AFP report said that in what seemed to be a related incident, a man dressed as a police officer opened fire at a youth camp at Utoya, an island outside Oslo, killing four people.)

Seven people were killed and several more injured in the blasts. A spokeswoman for Prime Minister Jens Stoltenberg said he was “safe and not hurt.”

Stunned office staff and civil servants working in the vicinity of the bombed building said at least two explosions could be heard in close succession, as the sound of the blasts echoed across the city.

Giant clouds of light-coloured smoke continued to rise hundreds of feet into the air over the city as a fire burned in one of the damaged structures, a six-storey office building that houses the Oil Ministry.

The police said the initial blast occurred at around 3.20 p.m. local time.

“We think there was more than one blast,” said Runar Kvernen, spokesman for the National Police Directorate under the Ministry of Justice and Police.

The cause of the explosions was not immediately clear, but a Reuters reporter described seeing the mangled wreckage of a car near one of the buildings. Photos and television footage showed windows blown out in the 17-storey office building across the street from the Oil Ministry, and the street and plaza areas on each side were strewn with glass and debris.

The centre of the city, Norway's capital, was sealed off, and police said they were on heightened alert as they combed through the debris in search of clues.

The explosions, which ripped through the cluster of modern office buildings around the Einar Gerhardsens plaza, occurred at a time when many Norwegians were on vacation and many more had left their offices early for the weekend. — New York Times News Service

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