The leading Democratic presidential candidates reacted to the mass shooting in San Bernardino, Calif., on Wednesday with calls to stop gun violence. The Republican candidates offered thoughts and prayers to victims, first responders, and others affected by the killings but did not mention gun laws or gun violence more generally.

Below is a sampling of the early reactions the candidates offered on Twitter:

Democrats

Hillary Clinton: I refuse to accept this as normal. We must take action to stop gun violence now. -H

Bernie Sanders: Mass shootings are becoming an almost-everyday occurrence in this country. This sickening and senseless gun violence must stop.

Martin O'Malley: Horrifying news out of #SanBernardino. Enough is enough: it's time to stand up to the @NRA and enact meaningful gun safety laws

Republicans

Donald Trump: California shooting looks very bad. Good luck to law enforcement and God bless. This is when our police are so appreciated!

Jeb Bush: Praying for the victims, their families & the San Bernardino first responders in the wake of this tragic shooting.

Ben Carson: My thoughts and prayers are with the shooting victims and their families in San Bernardino.

Gov. Christie: Praying for all those victimized by the shootings in San Bernardino, California today.

Ted Cruz: Our prayers are with the victims, their families, and the first responders in San Bernardino who willingly go into harm's way to save others

Lindsey Graham: Thoughts & prayers are with #SanBernardino

Mike Huckabee: Praying for those impacted by the shooting in California today.

John Kasich: My thoughts & prayers go out to those impacted by the shooting in San Bernardino, especially the first responders. -John

George Pataki: Praying for the victims and first responders in #SanBernardino for a quick resolution.

Rand Paul: My thoughts and prayers are with the victims, families, and brave first responders during this unspeakable tragedy.