President Barack Obama called the families of victims of Saturday’s deadly shooting in Tucson that left U.S. Rep. Gabrielle Giffords in critical condition with a gunshot wound to the head.

He spoke to GIffords’ husband, Mark Kelly and Arizona District 4 Rep. Ed Pastor Saturday after the shootings, said a news release from the White House. On Sunday, he talked to the families of two of those killed in the shooting: 9-year-old Christina-Taylor Green and Giffords’ staff member Gabe Zimmerman. He also talked U.S. Sens. Jon Kyl and John McCain Sunday.

Obama talked with House Republican and Democrat leaders during the weekend and plans to continue making calls throughout the week, according to the news release.

“The president is assuring them that all is being done to try and get to the bottom of this. He is offering his full support and thoughts and prayers on behalf of himself, Michelle and the entire nation,” the release said.