Updated at 10 a.m. ET
Heavily armed gunmen went on a shooting rampage through the city of Culiacán, the capital of Sinaloa state on Mexico's Pacific coast, battling security forces after authorities attempted to arrest a son of imprisoned drug lord Joaquín "El Chapo" Guzmán.
The gunfire from what appeared to be sniper rifles and truck-mounted machine guns sent residents of the western city scrambling for cover. Burning vehicles littered the streets as the gunmen faced off against the National Guard, army and police.