More than 100 people, many of them in wheelchairs who were attending a program for people with cerebral palsy, were evacuated yesterday afternoon from a Northeast Washington building after being exposed to carbon monoxide fumes.

Five were taken to George Washington University Hospital for minor exposure to the fumes, fire officials said.

D.C. fire officials said a gasoline-powered saw used by a contractor about noon caused a moderate buildup of the gas inside the International Business Mall building in the 1800 block of New York Avenue NE.

The building houses several businesses and a day program run by the United Cerebral Palsy organization. None of those involved in that organization and no one who suffers from cerebral palsy was taken to the hospital for treatment, authorities said.

The evacuees were sheltered from the heat in tents after being escorted out of the building. They were driven home in vans after emergency workers evaluated them.

Some people inside the building initially complained of headaches and nausea, authorities said. One of the five people taken to the hospital also suffered from asthma, officials said.

Firefighters and paramedics evaluated 110 people at the scene and gave oxygen and water to about 30, said Alan Etter, a fire department spokesman.

Etter said emergency workers took special care in evaluating those with cerebral palsy because they were wheelchair-bound and had difficulty communicating.

Firefighters and employees in the building said the contractors were operating a gas-powered saw and did not properly ventilate the area. Fumes from the saw's exhaust quickly filled the building, fire officials said.

Workers with the contractor, Brookbank Core Drilling & Sawing Inc., declined to comment at the scene. They referred questions to a supervisor, who declined to give his name and said he was looking into what happened. An employee who answered the telephone at Brookbank's offices in Waldorf said the company had no comment on the incident.

Carbon monoxide is an odorless gas that can cause headaches and dizziness in moderate amounts. Exposure to high levels of the gas can cause unconsciousness, brain damage and death.

Several employees in the building said they didn't know anything was wrong until firefighters told them to evacuate.

"We were not aware of it until the firefighters came and told us to leave the building," said Greg Okure, a project manager for Micon Construction Inc., a company on the building's second floor.

People evacuated from a building in the 1800 block of New York Avenue NE in the District gather in the shade of a tent.A woman exposed to fumes in the International Business Mall building is monitored. Five people were sent to George Washington University Hospital.