A fire at a mobile home in southeastern Texas killed five people, authorities said Monday.

The fire was reported around midnight Sunday, the Brazoria County sheriff's department said. A couple and their two children were killed, along with a third child, officials said.

The children were ages 1,4 and 7.

The cause of the blaze was not known. Alvin is about 30 miles south of Houston.

Also, a house fire in Sioux City, Iowa, that was deemed suspicious killed two children Sunday afternoon, authorities said. Police spokesman Marti Reilly says authorities believe the children lived in the home, but he had no information on whether anyone else was in the house at the time.