Update, 2:52 p.m.
The standoff has ended and one person has been taken into custody, according to the Galveston Police Department.
The Galveston Police Department is blocking entrances to Stewart Beach on Galveston as they respond to a "person in crisis," a Galveston Police Department spokesman said.
Few details were immediately available, but armed police could be seen pointing weapons toward a white van and a black truck parked next to each other the beach at 2:15 p.m.
The person has threatened to harm themselves and is alone, Galveston Police Department spokesman Sgt. Xavier Hancock said. Police believe the man may be armed, he said.
"We are taking the steps necessary to ensure the safety of everyone," Hancock said.
Stewart Beach is located at the east end of Broadway and is one of the most popular beach parks on the island.
This is a developing story. Check back later for more details.