PALM SPRINGS, Calif. -

Palm Springs police spent Friday morning trying to determine how five explosive devices ended up near the intersection of North Indian Canyon Drive and San Rafael Drive and who put them there.

The latest device was found shortly after 3 p.m. on Thursday.  A resident along the 300 block of San Rafael Drive called police to report a device was in his driveway.

Police called the Riverside County bomb disposal team to detonate the device, said spokesman Mike Kovaleff.  Afterward, mounted police searched the area for more devices -- a search that turned up nothing.

The discovery of the devices began Tuesday in Palm Springs when a 91-year-old man found what he believed was a pipe bomb. 

Kovaleff said the man kept the device overnight, and his son brought it to Palm Springs police headquarters, 200 South Civic Drive, on Wednesday afternoon.  The department was evacuated and the device was detonated on the front lawn of the police station.

Thursday morning, Kovaleff said the same man found another explosive device and called police.  When officers arrived they found two more, shutting down San Rafael Drive for most of the day.

Few details are being released about the investigation.  Kovaleff will only say the 91-year-old resident and his son were being cooperative with the investigation, and no one had been arrested.

Still, residents said they're fearful of the neighborhood.

"We are on Indian Canyon about a block away in an apartment complex," said one nearby resident on KESQ's Facebook page. "I'm worried that whoever is doing this might drop one closer to where we have kids."

"I live down San Rafael," said another resident.  "My apartment complex is full of families with kids.  This is scary stuff.  I hope they find out who is doing this."

Kovaleff urged the public not to try and move any device they think may be an explosive.  Instead, he said to use a landline telephone to call 911.  Cell phones are often used as triggers, he said, and it can be dangerous.

If you have any information about the explosives found in Palm Springs, call the Palm Springs Police Department at 760-323-8116 or Crime Stoppers at 760-341-STOP.