LOS ANGELES — A violent attack against a DASH bus driver in South Los Angeles on Sunday has renewed calls for action to address safety concerns among transit riders and employees.

This latest incident comes just two days after dozens of Metro bus drivers reportedly staged a “sick out,” over safety issues, prompting Metro to warn riders about service delays.

It also comes after two stabbing attacks against Metro drivers in April, and one deadly stabbing attack against 67-year-old Mirna Soza Arauz, a grandmother who was on her way home from work when she was killed at the Universal City station.