A series of aftershocks continues to rock the devastated central Italian city of L'Aquila, as the death toll from Monday's earthquake climbed past 200.

The U.S. Geological Survey put the magnitude of one aftershock at 5.6. The tremors, are sending rescue personnel scrambling. 

Workers and survivors in the walled city of L'Aquila have been clawing through mounds of rubble searching for victims

The Italian news agency ANSA puts the latest death toll at 228.

Earlier, Prime Minister Silvio Berlusconi said 150 people have been pulled alive from the rubble since the quake struck hours before sunrise Monday. 

U.S. President Barack Obama telephoned Mr. Berlusconi to express the deepest condolences of the American people to the families of the victims and those injured in the quake. The president assured Mr. Berlusconi the United States stands ready to help the Italian people in their time of need.

Mr. Berlusconi has promised that no one will be abandoned.  He canceled a planned trip to Russia and declared a state of emergency in the affected region, where towns and villages were severely damaged or flattened.

U.S. scientists measured the initial quake at magnitude 6.3.

Some information for this report was provided by AFP and Reuters.