New Mexico Gov. Susana Martinez vowed that whoever set off explosions outside two churches less than 30 minutes apart on Sunday "will feel the full pressure of the law."
At an evening news conference, Martinez also described the explosions — which occurred Sunday morning outside Calvary Baptist and Holy Cross Roman Catholic churches in the southern New Mexico city of Las Cruces — as the acts of a "coward."
The blasts caused only minor structural damage as worshippers gathered for morning services. One was set off in a mailbox, the other in a trash can just minutes later. No one was injured and no suspects were immediately identified.
Monsignor John Anderson of Holy Cross told the Las Cruces Sun-News that he was in the middle of administering communion when the bomb exploded.
"I was right in the middle of saying the words 'Take and eat, this is my body' and there was a pow! I mean, I knew it had to be more than a gunshot," he said. "I didn't know if it was a shotgun blast ... But it was very loud and I just kept on saying the words."
New Mexico state Police Chief Pete Kassetas told reporters that while the bombs were intended to terrorize churchgoers, authorities had not yet deemed them acts of domestic terrorism.
At the news conference, however, Martinez had a message for whoever was behind the twin bombings: "If your intention was to bring fear to those who worship, you have failed."
Officials from the FBI, Bureau of Alcohol Tobacco, Firearms and Explosives, and the Department of Homeland Security were assisting with the investigation.