On Friday night, Muslim Americans gathered at the Islamic Center of Hawthorne, in Southern California, to discuss the issue on so many of their minds: Islamophobia.

They talked about its definition, outlined its origin and expressed hope for its elimination.

Then they became its latest victims.

On Sunday morning, barely a day after the gathering, members arriving early to the Islamic center found the message “Jesus is the way” scrawled outside in spray paint. Just a few blocks away, the Ahmadiyya Muslim Community Baitus-Salaam Mosque was also vandalized with the word “Jesus.”

Sitting in the mosque’s driveway was what appeared to be a hand grenade.

The grenade turned out to be fake, but the fear felt by Southern California’s Muslim communities is very real. The pair of incidents in Hawthorne came just two days after another mosque in Coachella Valley, two hours to the east, was set ablaze. Police have said they are investigating the trio of attacks as possible hate crimes.

All three incidents occurred within 75 miles of San Bernardino, where a couple, who federal officials say were inspired by Islamist extremists, killed 14 people at a Dec. 2 holiday party.

The spate of anti-Islam vandalism comes as Muslims in Southern California have rallied in support of the victims of the San Bernardino attack. On Thursday, a group called Muslims United for San Bernardino announced that it had raised $180,000, or nearly four times its target, to support families of the victims. And on Sunday, the day the graffiti was discovered, Muslim leaders joined Los Angeles’s mayor and police chief at a rally against violence and extremism at Los Angeles City Hall.

“This type of behavior is born out of ignorance and fear,” Ahsan M. Khan, chapter president of the Ahmadiyya Muslim Community, told the Associated Press. “It’s through peaceful dialogue that we can hopefully see less of this type of hate crime,” he said.

Muslims in Southern California were on edge before the weekend’s attacks. Across the country, Islamic organizations argue that their members have come under increased attack as a result of the San Bernardino shooting and the increasingly harsh political rhetoric following the tragedy. Donald Trump, in particular, has drawn criticism for calling for a ban on Muslims being allowed into the United States as he continues to lead the Republican presidential field in national polling.

Shortly after the San Bernardino shooting, a Muslim shop owner in New York was savagely beaten by a stranger promising to “kill Muslims,” a severed pig’s head was tossed outside a mosque in Philadelphia, and a Muslim man in northern California was harassed, hit and splashed with coffee by a Christian woman while he was praying in a public park.

On Tuesday, a Somali restaurant in North Dakota was firebombed days after it was defaced with Nazi symbols and the words “go home,” according to the Grand Forks Herald. Police are now searching for a 25-year-old suspect.

Nowhere, though, have tensions flared hotter than in Southern California.

In Riverside, a city neighboring San Bernardino, a routine mall burglary quickly morphed into false social media rumors of another mass shooting last week. In Corona, another neighboring city, mosque leaders told The Washington Post that someone drives by and shouts hateful messages almost every night. And in Redlands, someone scrawled “F— muslims” on the apartment where the San Bernardino attackers had lived.

Southern California’s simmering cauldron boiled over Friday when a blaze erupted at the Islamic Society of Coachella Valley. Witnesses described hearing a “loud boom,” according to the Desert Sun. Four or five people were praying inside the mosque when the fire started, but the blaze was extinguished quickly and nobody was hurt, according to CNN. Reymundo Nour, the mosque’s acting imam, told the Desert Sun that the mosque had been “firebombed.”

“As far as we’re concerned, it is an act of terrorism,” Nour told NBC News. “The individual targeted us, we believe that it was targeted.”

On Friday evening, authorities arrested Carl James Dial Jr. for arson, hate crime and burglary.

The 23-year-old’s parents expressed little sympathy for their son.

“We will supply him with money for the commissary. We have no plans to bail him out. He’s an adult,” Dial’s father, John Dial, told NBC. “We both said right there, we said to him, I hope you like reading books, because you’re in it for the long haul. He’s a man.”

The vandalism at the Islamic Center of Hawthorne and at the Ahmadiyya Muslim Community Baitus-Salaam Mosque came less than a week after the head of the global Ahmadiyya Muslim Community warned of a third world war if Muslims and non-Muslims did not work together to find peace.

“The world stands in grave danger,” Hazrat Mirza Masroor Ahmad said, “and so we must bow down in prayer.”

Looming above the now-defaced mosque is a sign, apparently disregarded by the vandals.

The sign reads simply: “Muslims for Peace.”