STOCKTON (CBS13) — Many parents are still shaken up after several schools received bomb threats, which forced administrators to lock down campuses.

The threats were delivered electronically and investigators said businesses also received the same e-mail.

Christina Gonzales was among the many people who received a scary phone call.  It was about a situation at her granddaughter’s school.

“I was kind of frightened. I just left my work and I came to pick up my granddaughter,” she said.

The threat was sent electronically to Delta Sierra Middle School. Officers investigated and later determined the threat was a hoax.

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“I don’t think its funny because sometimes we need to take these threats seriously and try to find the person that is doing this because it’s frightening the people. My granddaughter called me crying,” she said.

The same e-mail threat was sent to other schools like Lincoln Technical Academy, Lockeford, Houston, Millswood and Tokay High. It was also sent to campuses across the country.

“We sent officers to the schools and to businesses, just to make sure everything was safe because the number one priority here is to make sure everyone is indeed safe,” said Joe Silva, Stockton Police Department.

Businesses and some government buildings in Sacramento and Placer Counties were also hit with the e-mail. The FBI is aware the threats were made across the country and is providing assistance to law enforcement agencies.

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“We have alerted the regional terrorism task force we are working with them as well as our high tech crime bureau, they are looking things as well all the demands that we are seeing are pretty consistent and they are demanding pretty specific things, and very specific language,” said Sgt. Shaun Hampton, Sacramento Sheriff’s Department.

Police in Stockton and school administrators from the impacted schools said at no time were students or staff in any danger and schools did return to their regular routines.