A woman in a trenchcoat opened fire with a long gun inside celebrity pastor Joel Osteen’s megachurch in Texas before being gunned down by two off-duty officers who confronted her, sending worshippers rushing from the building between busy Sunday services, authorities said.

The woman entered the Houston church with a 5-year-old boy shortly before 2pm and the child was shot and critically injured. Houston Police Chief Troy Finner said it was not clear whether the child was struck by the off-duty officers who returned fire. He said a 57-year-old man also was shot and wounded.

The child was in critical condition at a children’s hospital, while the man was stable at a different hospital with a hip wound.

Emergency vehicles line the feeder road outside Lakewood Church during a reported active shooter event. Photo / AP

Finner said that after the woman began shooting, both officers “engaged” her and the woman was killed. He said that unfortunately “a 5-year-old kid was hit” although he released no immediate details on how the confrontation unfolded.

He praised the officers for quickly confronting the woman, adding, “She had a long gun, and it could have been a lot worse.”

The slain woman was not immediately identified, and her motive wasn’t clear.

The shooting happened between services at the megachurch that is regularly attended by 45,000 people every week, making it the third largest megachurch in the US, according to the Hartford Institute for Religion Research. Osteen’s televised sermons reach about 100 countries.

Pastor Joel Osteen speaks to the media after a shooting at Lakewood Church, in Houston. Photo / AP

It was not clear where Osteen was at the time. But he joined police at a news conference afterwards and said the church is “devastated.” He added that the shooting could have been much worse if it had happened during the larger 11am service. He added he would pray for the victims and for the woman who did the shooting and their families.

“We’re going to stay strong and we’re going to continue to, to move forward,” Osteen said after authorities spoke. “There are forces of evil, but the forces that are for us - the forces of God - are stronger than that. So we’re going to keep going strong and just, you know, doing what God’s called us to do: lift people up and give hope to the world.”

Witnesses told reporters that they heard multiple gunshots shortly before the church’s 2pm Spanish language service was set to begin.

Christina Rodriguez, who was inside the church, told Houston television station KTRK that she “started screaming, ‘There’s a shooter, there’s a shooter,’” and then she and others ran to the backside of a library inside the building, then stood in a stairway before they were told it was safe to leave.

Longtime church member Alan Guity, whose family is from Honduras, said he was resting inside the church’s sanctuary before the 2pm service as his mother was working as an usher when he heard gunshots.

Houston Police officers watch over displaced churchgoers outside Lakewood Church. Photo / AP

“Boom, boom, boom, boom and I yelled, ‘Mom,’” he said.

The 35-year-old ran to his mother and they both laid flat on the floor and prayed as the gunfire continued. They remained there for about five minutes until someone told them it was safe to evacuate. Outside, Guity said, he and his mother tried to calm people down by worshipping and singing in Spanish, “Move in me, move in me. Touch my mind and my heart. Move within me Holy Spirit.”

Guity was among the many congregation members who waited Sunday evening to be allowed to return to their vehicles as police continued to search the building. The church is located in what used to be an arena where the NBA’s Houston Rockets used to play years ago.

A woman holds her face as she waits with others outside Lakewood Church. Photo / AP

Texas Governor Greg Abbott issued a separate statement saying “our hearts are with those impacted by today’s tragic shooting and the entire Lakewood Church community in Houston. Places of worship are sacred.”

At least 20 police and fire trucks were near one of the church’s entrances Sunday afternoon, including the fire department’s hazardous materials truck. Finner said it was reported that the woman had a bomb, but no explosives were found when her vehicle and backpack were searched.

Worshippers could be seen leaving the building as authorities evacuated the church before the news conference. Officials announced a reunification centre had been set up at a nearby gym for people to find their loved ones.

A woman stands outside Lakewood Church, in Houston, after a reported shooting during a Spanish church service. Photo / AP

The church has grown tremendously over the past 25 years since Joel Osteen took over after his father’s death in 1999 and introduced an upbeat style of Christian televangelism that has captured a following of millions. The elder Osteen founded the church in a converted feed store in 1959.

At times, Lakewood Church has served as a shelter during flooding in Houston. After the pandemic, it reopened for a time at one-quarter of its capacity with only 4000 worshippers allowed.