SAN FRANCISCO (KRON) — All lanes are back open on the Bay Bridge following a severe traffic alert on the westbound deck due to police activity Friday morning, according to the California Highway Patrol. The activity was west of Treasure Island Road and the right lanes on the bridge were blocked.

Motorists were advised to expect delays and to use alternate routes if possible. Residual delays are still expected.

The activity was first reported around 8:35 a.m. No other details were immediately available.

This is a developing story. Check back for updates.