The FBI is investigating two small explosions that happened Sunday morning at churches in Las Cruces, New Mexico.

The first device went off around 8:00am local time in a mailbox at Calvary Baptist Church, shaking the building while about 30 congregants waited for mass to begin.

Then, a second explosion was reported about 30 minutes later at Holy Cross Catholic Church in a garbage can outside the entrance. 

That blast occurred while worshippers were inside receiving Communion. No one was injured in the blasts and minor damage was reported.

Federal authorities are looking into whether the incidents are related.

The Las Cruces Sun-News reported:

At a press conference Sunday night, Gov. Susana Martinez said that only a "coward" would place an explosive device in a church. She vowed that the person responsible would be caught, and urged people to continue to attend church services.

"Whoever did this will feel the full pressure of the law," she said. "If your intention was to bring fear to those who worship, you have failed."

State Police Chief Pete Kassetas said the acts were certainly intended to terrorize churchgoers, but he could not call it an act of terrorism at this time, or even confirm for certain that the two explosions were related.

Kassetas did not specify on the type of devices that were used, but said they "were not fireworks" and believes they were meant to harm churchgoers.

One churchgoer, a former Marine, told the paper that the device appeared to be a "real bomb," explaining that he could recognize parts typically used by bomb-makers.

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Watch Lauren Green's report from this morning.