A Continental Airlines Inc. flight rocked by turbulence that injured at least 26 passengers may be investigated by U.S. safety officials.

The National Transportation Safety Board is determining whether yesterday’s incident meets the legal criteria for an aircraft accident, Peter Knudson, a spokesman, said today in an interview. If so, the agency will open a formal inquiry, he said, with a decision to be made “within the next few days.”

“We’re still assessing the injuries and gathering information,” Knudson said. “We are getting data from the cockpit voice recorder and the flight data recorder.”

The NTSB investigates aviation accidents to determine a cause and issue safety recommendations. Turbulence accounted for 22 percent of all U.S. airline accidents from 1996 to 2005 and was responsible for 49 percent of the serious-injury accidents, the NTSB said in a report in March.

Some of the 168 passengers on Flight 128 were tossed from their seats when the Boeing Co. 767-200 encountered clear-air turbulence near the east end of the Dominican Republic about 900 miles (1,448 kilometers) from Miami. The jet, which carried 11 crew members, was en route to Houston from Rio de Janeiro and diverted to Miami.

One person injured on the flight remained hospitalized today, said David Messing, a spokesman for Houston-based Continental. The plane was flown to Houston for repairs to the cabin interior, he said.

Continental is the fourth-largest U.S. airline based on miles flown by paying passengers.