SANTA FE, Texas — [Update 11:58 a.m.] A Texas official says explosive devices found with the suspected gunman at a high school near Houston weren't capable of detonating.

Galveston County Judge Mark Henry said Saturday that authorities found a group of carbon dioxide canisters taped together, and a pressure cooker with an alarm clock and nails inside. But he says the canisters had no detonation device and the pressure cooker had no explosive material.

Henry also says police exchanged "a lot of firepower'' with the gunman before the Santa Fe High School student surrendered.Various explosive devices have been found around Santa Fe High School, according to Texas Gov. Greg Abbott.

ORIGINAL STORY - During a press conference at Santa Fe High school, Abbott said a CO2 device and a Molotov cocktail were found in a home and a vehicle.

Search warrants have been granted to search two residences law enforcement believes to be connected to the shooter.

Abbott added investigators are taking caution during the investigation due to the potential for more explosive devices to be found in these residences.

Earlier, the Santa Fe Independent School District tweeted explosive devices had been found at the school and off campus.

Law enforcement is asking community members to be on the lookout for suspicious packages and anything that looks out of place.

They are asking anyone with information including photos or videos depicting Friday's events is asked to contact the command center at 409-927-3310.