A homeowner fatally shot three people who invaded his mobile home near Houston, Texas, and was wounded himself in a brief gun battle, authorities say.

Two males living in the mobile home saw three men enter their residence on Monday morning in Channelview, about 16 miles (25 kilometers) east of Houston, Harris County Sheriff Ed Gonzalez told reporters.

Gonzalez said one of the mobile home occupants escaped while the other fired a shotgun at the intruders, killing all three.

It appears there was some type of gunfire exchange. The one with shotgun was able to shoot at the three males and they were all pronounced deceased here at the scene, Gonzalez said.

There may be a fourth suspect who fled the scene, he said.

The homeowner who fired on the three men was shot during an exchange of gunfire. Gonzalez said he was in serious condition.

We�re going to have a lengthy follow-up investigation out here at the scene. Having three dead bodies inside a home is not something very common, Gonzalez said.

The wounded survivor was undergoing surgery and unlikely to face criminal charges as he had the legal right to defend his home, Gonzalez said.

In Texas, a law known as the castle doctrine allows people to defend themselves from intruders in their homes.

Mass shootings have been occurring across the US with increasing frequency.

Last year, Amnesty International warned that the gun violence situation in the US has grown into a full blown human rights crisis and the administration of President Donald Trump was doing little to solve it.

In a scathing report, the rights group warned that all aspects of American life have been compromised in some way by the unfettered access to guns, with no attempts at meaningful national regulation.

The issue of gun violence has become all the more polarizing under Trump, a Republican, whose presidential campaign was funded partially by the National Rifle Association (NRA), an influential gun lobby in the US.