DALLAS?-- A suspect in the fatal shootings of four people in two Dallas-area homes was in custody Thursday as police tried to determine what prompted the attacks just minutes apart and whether an explosive was used.

Four people were wounded in the late Wednesday shootings. Investigators arrested Erbie Bowser at the second location, but they have no information about Bowser's relationship with any of the victims, DeSoto police Cpt. Melissa Franks said.

Charges were pending, Franks said.

Police were called to a home where they found four gunshot victims, two of whom had died, Dallas police Sgt. Warren Mitchell said. The suspect then fled to the nearby community of DeSoto, where he is suspected of killing two people. Two boys, aged 11 and 13, survived that attack.

Police did not immediately release the identities of those killed and wounded, and the conditions of the survivors were not known Thursday.

A neighbor in DeSoto, Tommy Johnson, said he heard a loud boom Wednesday night. "I peeped out the front, and that's when I saw a bunch of officers walking down the sidewalk and about 10 houses up," Johnson said.

Franks said she could not confirm that a grenade or other explosive device had been used in the DeSoto attack, pending the results of a federal and Dallas bomb squad investigation.