SAN FRANCISCO, Jan. 1 (Xinhua) -- Seven people were wounded, two of them seriously, after a truck plowed into pedestrians and a car in San Francisco on the U.S. west coast on Monday, the San Francisco fire department said.

The collision occurred in the area around 21st Avenue in downtown San Francisco, involving the box truck, two pedestrians, and a car occupied by a family of five.

"The two serious injuries have been sent to the TRAUMA center," San Francisco Fire tweeted.

An elderly person suffered life-threatening injuries, while another elderly person was seriously injured, a local TV report said. Both men were in their 60s and 70s, respectively.

The other five people suffered minor injuries and were being evaluated at the scene.

The crash was being investigated, police said.