TIANJIN -- Five people have been detained after a bus accident with 26 deaths early July in North China's Tianjin city, police said Sunday.

The five, identified by the surnames Wu, Li, Fu, Liu and Zhao, have been implicated in causing the serious accident, according to the city's public security bureau.

The five jointly bought the bus in 2011 and applied for long-distance passenger transport. In the pursuit of profit, they illegally changed its regular operating route and manipulated the vehicle's positioning system to avoid being tracked by authorities. They also used the bus to deliver cargo for logistics firms.

The coach was carrying 30 people when it careered through the guardrail at the Baodi section of the Tianjin-Jixian expressway on the night of July 1. The four survivors -- a ticket tout, the codriver and two passengers -- sustained slight injuries.

The driver lost control of the vehicle due to a flat tire. The investigation continues.