WASHINGTON (AFP) - A distraught father of a patient in a Texas hospital surrendered to the police after a stand-off, the police said on Saturday.

The sheriff's office for Harris County issued a statement that the man had surrendered and the hospital, just north of Houston, was no longer under lockdown.

Previously, the police had said the man was holding hostages and could be armed. Later, they said it was not a hostage situation and the father was not armed.

Police described the father as "distraught about his son's medical condition". He was with his son in the critical care unit of the Tomball Regional Medical Centre.

"The suspect has surrendered without incident," the sheriff's office said.

The sheriff's office indicated around 8pm local time on Saturday night that it had deployed its High Risk Operation Unit to Tomball Regional Medical Centre outside Houston.

"At this time preliminary information is that a man is holding at least two people hostage inside the hospital," the sheriff's office said on its website.

Local NBC television affiliate KPRC-TV cited witnesses inside the medical centre as saying the hospital had been shut down as the authorities tried to defuse the crisis. However, Texas news channel ABC 13 quoted the police saying that though the floor that the hostage situation is taking place has been evacuated, the hospital has not been shut or put on lockdown.

ABC 13 reported the sheriff's office as saying that the man is distraught about his son's medical condition and is with him inside the hospital room in the critical care unit.

It also reported that the man had barriacaded himself in a room with a person who is believed to be a family member.

He has not made any demands, and no staff members are being held hostage, ABC 13 quoted the police as saying.

"He is believed to be armed at this time," ABC 13 quoted Detective Jimmy Harral with the Tomball Police Department as saying. "At this time they are negotiating with him for a peaceful surrender. He hasn't been asking for anything at this time, nothing in particular."

The hospital has 238 active doctors on its staff, and more than 350 beds, the International Business Times reported. It is about 30 minutes from the centre of the Texan city of Houston.

United States House Representative Michael McCaul, a Republican whose ward includes Tomball, tweeted: "Keeping all of those in Tomball in my thoughts and prayers."