Two staff members of Congressman Gerry Connolly, D-Va., were hospitalized after an attack Monday morning by a person carrying a metal baseball bat. Connolly shared news of the attack on social media Monday afternoon.

“This morning, an individual entered my district office armed with a baseball bat and asked for me before committing an act of violence against two members of my staff,” wrote Connolly, who represents Virginia’s 11th District in Fairfax.

The attack occurred just before 11 a.m. at Connolly’s office in the City of Fairfax. According to Fairfax City Police, the victims of the attack were treated for non-life-threatening injuries. Police arrested a suspect, identified as 49-year-old Xuan Kha Tran Pham of Fairfax. The motive for the attack is unclear, police say.

A joint investigation is underway by U.S. Capitol Police, the Federal Bureau of Investigation, and Fairfax City Police.

By Tuesday, Pham had been charged with felony aggravated malicious wounding and malicious wounding in the incident.

The attacker struck a senior Connolly aide in the head, according to CNN reporter Manu Raju, who spoke with Connolly. The other victim, an intern on her first day on the job, was hit in the side, according to Raju.

The attacker was a constituent, but someone Connolly did not know, according to Raju. The attack left widespread damage, including broken glass and damaged computers, Raju reported. The suspect is facing charges of one count of aggravated malicious wounding and one count of malicious wounding.

Connolly was out of the office at an event at the time of the attack.

Pham also instigated an altercation earlier that day when he approached a woman parked in her car, asked if she was white, and then hit her windshield with a baseball bat, the Associate Press reports. A video recorded from a nearby neighbor’s home shows a man with a bat chasing a woman who is screaming. He’s being charged with a hate-crime-related assault and felony destruction of property charges for that incident.

Pham had been diagnosed with schizophrenia, his father, Hy Pham, told the Washington Post. His father had been trying to get mental health care for his son.

The AP reports Pham had assaulted police and tried to take a gun from responders officers after calling dispatch saying he wished to harm others.

Many elected officials in Virginia condemned the assault, including Gov. Glenn Youngkin and Attorney General Jason Miyares, both Republicans.

“Violence does not belong in our political system and my prayers are with Rep. Gerry Connolly’s staff for a speedy recovery,” wrote Youngkin on social media. “We’ve seen this against our judiciary, we’ve seen this against our legislative branch, and it has no place in our Commonwealth.”

Miyares similarly said he hoped the staffers who were attacked recover quickly. “The coward who did this should be prosecuted to the fullest extent of the law,” Miyares wrote on social media.

The attack is the latest in a series of violent incidents targeting elected officials. The number of threats against members of Congress has increased fourfold in the past six years, according to U.S. Capitol Police. There were more than 9,000 over the past year.

“I cannot overstate the scope, breadth, and intensity of the nation’s current threat climate. Hate, intolerance, and violence are part of this disturbing trend,” USCP Chief Tom Manger testified recently before the U.S. Senate.

In his statement, Connolly praised his staff and said he was focused on “ensuring they are receiving the care they need.”

“My District Office staff make themselves available to constituents and members of the public every day. The thought that someone would take advantage of my staff’s accessibility to commit an act of violence is unconscionable and devastating,” Connolly wrote.

This story was updated with more information on previous incidents involving Pham.