PHILADELPHIA (AFP) - A shooting erupted at a courthouse in Wilmington, Delaware on Monday, leaving three people dead, including a gunman, police said.

"I can confirm a shooting at 8am. Two civilians, females, were killed, two capital officers were shot. The gunman is dead inside the lobby," a police spokesman said at a news conference.

The incident took place in the New Castle county court building, which was evacuated.

The police spokesman said multiple shots were fired and that police were searching the building floor by floor.

"The scene is still very dynamic inside," he said.

The area around the courthouse was surrounded by police, ambulances and fire trucks, televised images of the scene showed.