TAIPEI -- Two men in a van raised alarm Thursday when their vehicle crashed into the outer perimeter of Taiwan's Presidential Office building, but police said it was a case of drunk driving, not an act of malice.

Spokesman David Lee said that President Chen Shui-bian was in the building at the time of the crash, but was never in danger.

A police official said the crash occurred after the van's tires were flattened by protective spikes around the perimeter of the building, a sprawling, red-colored structure in downtown Taipei.

The official spoke on condition of anonymity because he was not authorized to talk to the press.

He said the driver, Su Kai, 49, was taken into custody together with a 54-year-old passenger whom he did not identify. Neither was injured in the incident.

Both men were interrogated, the official said, and police determined the incident occurred as a result of drunk driving.

He said the case has been given to prosecutors to determine if charges should be brought against the men.

Over the past three years Taiwan's Presidential Office Building has served as lightning rod for protests against Chen, who was re-elected by a razor thin margin in 2004, and has survived three recall attempts over allegations of systematic corruption involving his family and inner circle.