Four people were killed and eight injured in a shooting at a Mormon church in Michigan, officials said on Sunday.
A fire was started after a man, 40, crashed his vehicle into the front doors of the church and then opened fire on worshippers with a gun, Grand Blanc Township Police Chief William Renye told reporters.
He said more victims are expected to be found, and the gunman was also dead after a firefight with police.
"This incident was completely unnecessary and avoidable," Mr Renye said.
He said several shooting victims were in "critical conditions" and that the suspect had used an assault rifle.
Police said they were investigating a motive for the attack.
The shooting took place at The Church of Jesus Christ of Latter-day Saints in Grand Blanc, about 80km north of Detroit.
US President Donald Trump said he was briefed on the "horrendous" shooting and that the FBI was immediately dispatched to the scene. He said the shooting was "another targeted attack on Christians".
"The suspect is dead, but there is still a lot to learn," he wrote on his Truth Social network. "This appears to be yet another targeted attack on Christians in the United States of America."
He said the "epidemic of violence" in the country must end "immediately".
In a statement, Michigan Governor Gretchen Whitmer said her heart was breaking for the community.
“Violence anywhere, especially in a place of worship, is unacceptable,” she said.
Three people were killed and eight others were injured on Saturday night after a gunman on a boat opened fire on a bar in North Carolina.
The shooter who had used an assault rifle was detained by police and then charged.
The attacks come as the nation is still reeling from the shooting of Charlie Kirk, a right-wing commentator, who was shot dead this month while speaking at an event in Utah.
The shooting has brought to the fore deep divisions among Americans over the merits of free speech and gun ownership.
Mr Trump described the killing as a “dark moment for America”.
