Hundreds of registered nurses have planned another strike against East Bay hospitals affiliated with Sutter Health -- and this time the walkout will last at least seven days.

The strike -- part of a lengthy battle over wages, benefits and patient care issues -- will begin at 7 a.m. on May 17 and end at 7 a.m. on May 24, union leaders said. But it could last beyond that date if the hospitals hire replacement workers on longer contracts and lock out the striking nurses until those contracts end, as has happened in the past.

This will be the ninth time since September 2011 that nurses have struck Sutter hospitals in the East Bay.

Leaders of the California Nurses Association-National Nurses United noted that they have reached contract settlements with several other Sutter hospitals in the Bay Area, but not those in the East Bay.

Nurses will walk off the job at Alta Bates Summit Medical Center in Berkeley and Oakland, Eden Medical Center in Castro Valley, San Leandro Hospital and Sutter Delta Medical Center in Antioch.

A Sutter spokesman said replacement workers will be hired and the hospitals will remain open.

Sandy Kleffman covers health. Contact her at 510-293-2478. Follow her at Twitter.com/skleffman.