An errant lane change by the driver of a van contributed to an accident on Interstate 95 near Elkridge that left five people injured and snarled the highway for two hours yesterday, state police reported.

The driver of a Ford Windstar was traveling north on I-95 at the Montgomery Road exit about 2:45 p.m. when he attempted to move into a lane occupied by a 2000 Toyota Camry.

The Camry's driver blew her horn, prompting the van's driver to swerve abruptly and overturn, police said. The Camry then was rear-ended by a tow truck, police said.

The 24-year-old driver of the Camry and a child passenger in her car were taken to St. Agnes HealthCare. The tow truck driver, 29, was taken to Maryland Shock Trauma Center, and his two child passengers were taken to John Hopkins Hospital. None of the injuries was life-threatening, police said.

The driver and three passengers in the van, all wearing seat belts, were not injured, police said.