As Donald J. Trump canceled his campaign events in Miami and released a statement in response to the Dallas shootings, his campaign’s Virginia state chairman took to social media and explicitly blamed Hillary Clinton for them.

Corey Stewart, who is also reported to be planning a run for governor in Virginia in 2017, posted on Facebook as news of the shooting was breaking.

“Liberal politicians who label police as racists—specifically Hillary Clinton and Virginia Lt. Governor Ralph Northam—are to blame for essentially encouraging the murder of these police officers tonight,” Mr. Stewart wrote.

The Trump campaign condemned Mr. Stewart’s comments.

“Corey does not speak for the campaign and this is not something we agree with,” Hope Hicks, a campaign spokeswoman, wrote in an email.

Donald Trump Jr., Mr. Trump’s son, also has been active on social media since the shooting, retweeting Joe Walsh, the former congressmen and current radio host, sharing a news article that reported that Black Lives Matter protesters had been calling for the killing of police officers on Twitter.

The post was one of many Mr. Walsh has been sharing that have been fraught with racial tensions, and attempting to put blame on the Black Lives Matter movement and President Obama for the shootings.

Mrs. Clinton canceled some of her appearances but plans to follow through with others, including a speech at the African Methodist Episcopal Church conference in Philadelphia.