A California church that espouses anti-LGBT+ beliefs and has been the recent target of protests was bombed with an improvised explosive device early on Saturday morning, authorities said.
The El Monte police department responded to calls at about 4:30 a.m. about smoke at First Works Baptist Church. Officers discovered windows were broken and realised there had been a blast, Lt. Christopher Cano told reporters at the scene. There were no reported injuries in the explosion.
El Monte police, the Los Angeles County Sheriff's Office and the FBI responded to the explosion and determined there was not a second device.
Law enforcement is investigating who might be behind the blast, although there is no indication that activists protesting the church were responsible for the attack, El Monte Police chief David Reynoso told The Washington Post. Obscene messages in spray paint on the building found by responding officers were not related to the church’s anti-LGBT+ teachings, Mr Reynoso said.
"We don't have any information leading us to believe that the demonstrators in the past are in any way responsible for this," Mr Reynoso said.
The detonation was powerful enough to break a window in a neighbouring structure, FBI spokeswoman Laura Eimiller told The Post.
Federal agents are looking into a police report filed two weeks ago by the church's pastor, Bruce Mejia, about an arson threat sent on social media, Ms Eimiller said.
The church did not answer calls on Saturday.
Researchers at the Southern Poverty Law Centre have classified the church as one of 70 hate groups in the country that promote anti-LGBT+ sentiments.
It is part of the New Independent Fundamental Baptist Movement, fewer than two dozen churches in the United States that are associated with anti-LGBT+ pastor Steven Anderson. Mr Anderson has been banned from 34 countries for his rhetoric that calls for the deaths of LGBT+ people, according to the civil rights group.
The church's teachings condemning same-sex marriage have attracted criticism and protests. An online petition by Keep El Monte Friendly, a group that organised the protests against First Works Baptist Church, to expel the church from El Monte has received nearly 15,000 signatures.
Negotiations were ongoing between local authorities, the church and protesters to mitigate tensions, Ms Eimiller said.
Those talks included the city and county, Alma Martinez, El Monte city manager, told the Los Angeles Times.
"Even though we don't know at this time who is involved in the crime, as a city we want to make sure that we continue to work on de-escalating the situation to promote peace, safety and respect in our community," Ms Martinez told the newspaper. "Crimes of this nature are not acceptable."
Keep El Monte Friendly said in a statement that it did not condone the act of violence.
"Our movement was intended to bring light and awareness to the hateful rhetoric taught by this group," the activist organisation said of the church. "We understand that what they preach can make people upset. However, we would never promote, encourage or condone any violence or acts of harm."