Police responded to the 1700 block of Monrovia Drive for a report of suspects with a gun who had apparently jumped a fence and then fled.
Police tracked down a suspect vehicle and believe the suspects are holed up in a house near Sanders Elementary School at 3411 Rocky Mountain Drive, which prompted a lockdown at the school around 8:45 a.m.
At around 9:45 a.m., the lockdown was lifted at the school.
No injuries were reported in the incident, which police were still investigating as of 9:50 a.m.
Two other schools in the area, Ida Jew Academies at 1966 Flint Ave. and August Boeger Middle School at 1944 Flint Ave., were also briefly on lockdown this morning.
By 8:45 a.m., police had lifted that order as the police activity moved closer to Robert Sanders Elementary, said Lauri Breton, director of student services for the Mount Pleasant Elementary School District.
Police said the lockdowns were a precaution for the safety of the students and staff.
Breton said the school district was "being extra cautious."