US: 2 killed in explosion at manufacturing business in Houston

At least two people were killed due to an explosion at a Houston manufacturing business.

CNN quoted city Police Chief Art Acevedo as saying that a criminal investigation into the blast's cause is underway.

"We have no evidence at this point ... that an intentional act is involved. Having said that, part of our protocol is always to (start) a criminal investigation," he was quoted as saying.

Acevedo also tweeted that debris flew a half-mile from the explosion site.