A woman in a trenchcoat opened fire with a long gun inside celebrity pastor Joel Osteen鈥檚 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 2 p.m. 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 hospital, while the man was stable with a hip wound.

Finner said that after the woman began shooting, both officers 鈥渆ngaged鈥� her and the woman was killed. He said that unfortunately 鈥渁 5-year-old kid was hit鈥� although he released no immediate details on how the confrontation unfolded.

He praised the officers for quickly confronting the woman, adding, 鈥淪he had a long gun, and it could have been a lot worse.鈥�

The woman was not immediately identified, and her motive wasn鈥檛 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 U.S., according to the Hartford Institute for Religion Research. Osteen鈥檚 televised sermons reach about 100 countries.

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

鈥淲e鈥檙e going to stay strong and we鈥檙e going to continue to, to move forward,鈥� Osteen said after authorities spoke. 鈥淭here are forces of evil, but the forces that are for us 鈥� the forces of God 鈥� are stronger than that. So we鈥檙e going to keep going strong and just, you know, doing what God鈥檚 called us to do: lift people up and give hope to the world.鈥�

Witnesses told reporters that they heard multiple gunshots shortly before the church鈥檚 2 p.m. Spanish language service was set to begin.

Christina Rodriguez, who was inside the church, told Houston television station KTRK that she 鈥渟tarted screaming, 鈥楾here鈥檚 a shooter, there鈥檚 a shooter,鈥欌�� 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鈥檚 sanctuary before the 2 p.m. service as his mother was working as an usher when he heard gunshots.

鈥淏oom, boom, boom, boom and I yelled, 鈥楳om,鈥欌�� 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 worshiping and singing in Spanish, 鈥淢ove in me, move in me. Touch my mind and my heart. Move within me Holy Spirit.鈥�

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鈥檚 Houston Rockets used to play years ago.

Texas Gov. Greg Abbott issued a separate statement saying 鈥渙ur hearts are with those impacted by today鈥檚 tragic shooting and the entire Lakewood Church community in Houston. Places of worship are sacred.鈥�

At least 20 police and fire trucks were near one of the church鈥檚 entrances Sunday afternoon, including the fire department鈥檚 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 center had been set up at a nearby gym for people to find their loved ones.

Juan A. Lozano, The Associated Press