At least seven people are dead after another shooting incident in the US state of California.

The killings occurred at two locations in Half Moon Bay near San Francisco on Monday afternoon.

Police say at least four people were killed at one site and three at the other. The authorities also say that they have taken a 67-year-old male suspect into custody.

The incident follows a mass shooting just two days earlier at a ballroom dance studio in Monterey Park near Los Angeles. Police say the death toll from the case has risen to 11, after one of those injured died.

They say 42 shell casings have been recovered from the dance hall, where Lunar New Year celebrations were underway at the time of the attack.

Police have identified the suspect as a 72-year-old man of Asian descent. He was found dead from a self-inflicted gunshot wound.

California Governor Gavin Newsom tweeted, "At the hospital meeting with victims of a mass shooting when I get pulled away to be briefed about another shooting." He wrote, "Tragedy upon tragedy."