LOS ANGELES (CBSLA.com) — Seven people, including two children, were injured in two separate West Los Angeles crashes involving four vehicles, police said Tuesday.

The first crash happened at the intersection of Pico Boulevard and Crescent Heights about 10:30 p.m. Monday, Los Angeles police Sgt. Clifton Frazier said.

“There were two vehicles involved there,” Frazier said. “One person was injured in that cash.”

One of those two vehicles then left the scene and got involved in a second crash a few minutes later at the intersection of Pico and Robertson boulevards, west of the first crash site. One of the vehicles barreled through a bus bench and slammed into an unoccupied office building, Frazier said.

“In that second accident, we had three vehicles involved, including one of the two from the first one,” Frazier said. “That crash left six people injured at that location.”

Frazier said all seven people were transported to hospitals, but all of the victims were later released after being treated for moderate injuries.

“None of them were admitted to the hospital,” he said.

Investigators are still trying to sort out what happened.

“The driver of the vehicle claimed mechanical failure,” Frazier said. “But we don’t know at this point whether it was mechanical failure or a hit-and-run.”

Frazier said alcohol did not immediately appear to have been a factor.

“But we are going to turn over the investigation to our detectives, who will determine if it was mechanical failure or a hit-and run,” he said.

(©2016 CBS Local Media, a division of CBS Radio Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. Wire services contributed to this report.)