LAS CRUCES, N.M. — Two small explosions just 20 minutes and a few miles apart shocked congregants Sunday morning at two churches in southern New Mexico.

There were no injuries from the blasts outside Calvary Baptist Church and Holy Cross Roman Catholic Church in Las Cruces, a police spokesman, Danny Trujillo, said. Each building had minor damage.

Authorities were trying to determine who planted the explosives, what materials were used and whether the blasts were related.

“It doesn’t appear to be coincidental because of the timing, but you never know,” Mr. Trujillo said.