Nearly 25 suspects took part in a $1 million armed robbery at Heller Jewelers in San Ramon, California, police said.

The group used crowbars and pickaxes to smash cases before becoming trapped by automatic security doors, forcing one robber to fire a gun to escape.

Six getaway cars awaited nearby, but police, aided by drone footage and regional cooperation, arrested seven suspects from Oakland, ages 17 to 31, who are linked to similar Bay Area crimes, TV 6 News has reported.

Authorities recovered two guns, stolen vehicles, and some jewelry, and warn more arrests are expected as the investigation continues.