HOUSTON -

Two small explosions could be heard as law enforcement officials continued to execute a search warrant at a Memorial area home Saturday afternoon.

FBI spokesperson Shauna Dunlap said law enforcement officers discovered a "potential volatile substance" at the home in the 400 block of Fall River Drive, leading to two controlled detonations.

The first detonation happened shortly before 2 p.m. and the second a couple of hours later.

"For the safety of the nearby public, the safety of the nearby personnel, we needed to dispose of that substance in the backyard of the residence," said Dunlap.

Some neighbors said the sound caught them by surprise.

"It was pretty loud and we live a pretty good distance away. It was just a loud boom," said neighbor Robin Rosenberg.

On Friday, the FBI and other law enforcement agencies served a search warrant at two Houston homes, one in southwest Houston and the other at the Fall River address. Another was also served in Bryan.

While the two other homes were cleared Friday afternoon, officials remained at the Fall River home all day Saturday.

"You kind of wonder if you need to get out and leave," said resident Martha Crawford. "They were here all day day and all night and they're still here. It's scary."

Public records show the homes are owned by Cecily Horton and Andrew Schneck. They also own the condo in Bryan. It's still unclear what led FBI agents to the homes.

"Because the documents remain sealed in this case, we are not at liberty by court order to comment further on the operations or the ongoing investigation at this time," said Dunlap.