There are also reports that at least one other person attending the rally was also killed.

The Trump campaign is releasing a statement confirming Donald Trump is safe.

Trump had blood around his ear after shots may have been fired during his rally in Pennsylvania today.

While he was speaking in Butler, audible pops could be heard, and he was immediately tackled by Secret Service.

He was rushed off stage by agents while pumping his fist in the air and was driven off in a heavily protected vehicle.

His campaign has since released a statement saying Trump thanks law enforcement for their quick response during the incident and re-affirmed Trump is safe.

They say he's being checked out at a nearby medical facility.

An eyewitness to the Donald Trump incident at his Pennsylvania rally believes gun shots were fired.

Pennsylvania Senate candidate David McCormick said he heard what sounded like gunfire and he saw someone go down in the crowd behind Trump.

He added Trump is lucky to be alive.

Nikki Haley is condemning political violence and is offering prayers for Donald Trump.

The former South Carolina Governor posted "This should horrify every freedom loving American. We are lifting up Donald Trump, the entire Trump family, and all in attendance in prayer." Haley was Trump's rival in the presidential primaries before dropping out of the race earlier this year.

This is a developing story. Check back later for more details.