Democratic candidate Hillary Clinton spoke about the need for tighter gun control Wednesday while talking to reporters in Ankeny, Iowa. REUTERS

In the aftermath of the Virginia shooting Wednesday, politicians took to Twitter to express their grief and offer condolences to the friends and family of the two journalists killed by Vester L. Flanagan during a live television broadcast.

WDBJ reporter Allison Parker, 24, and cameraman Adam Ward, 27, were filming a live interview Wednesday morning when they were fatally shot by Flanagan, who went by the name Bryce Williams when he was employed at the news station.

Presidential candidates were among some of the politicians who tweeted condolences. Former Florida Gov. Jeb Bush wrote Wednesday morning that he was "shocked by the horrific murders."

Wisconsin Gov. Scott Walker called Parker and Ward's deaths a "tragic loss," while South Carolina Sen. Lindsay Graham tweeted that the shooting was "absolutely heartbreaking."

Fellow GOP candidate Ben Carson wrote that he sends his prayers to the station, as did Texas Sen. Ted Cruz.

Vermont Sen. Bernie Sanders and Florida Sen. Marco Rubio told followers that they were saddened by Parker and Ward's deaths, and had their families and friends in his thoughts.

Former Maryland Gov. Martin O'Malley denounced the shooting as "senseless."

Others called for stricter gun control. Former Secretary of State Hillary Clinton spoke to reporters in Ankeny, Iowa, Wednesday about the need for universal background checks for gun purchases. She also tweeted to followers that the country "cannot wait any longer" to push for gun control reform.