(CBS SF) – Four days after the tragedy in Newtown, Conn., two major retailers have announced that they are pulling certain kinds of semi-automatic rifles off store shelves.

Walmart announced Monday that the chain is pulling the Bushmaster Rifle from its web store, a military-style weapon similar to that used by 20-year-old Adam Lanza in the mass shooting that killed 20 children and six staff members Friday at Sandy Hook Elementary School.

READ MORE: KPIX Reporters Remember Slain Security Guard Kevin Nishita; 'Just the Kindest Man'

Lanza also fatally shot his mother Friday before killing himself.

Complete Coverage at CBS Connecticut

Complete Coverage at CBS New York

Photo Gallery: Connecticut Elementary School Massacre

The Bushmaster Rifle is not sold in California due to strict gun control laws.

Meanwhile, Dick’s Sporting Goods announced Tuesday morning that it will be suspending sales of certain kinds of semi-automatic rifles from its chain stores nationwide.

Walmart has 20 stores in the Bay Area. Dick’s has outlets in the Central Valley and in Southern California.

Dick’s issued a statement in response to the suspension:

READ MORE: UPDATE: News Crew Security Guard Shot in Oakland Dies From Injuries; Photo of Suspect Vehicle Released

“We are extremely saddened by the unspeakable tragedy that occurred last week in Newtown, CT, and our hearts go out to the victims and their families, and to the entire community.”

“Out of respect for the victims and their families, during this time of national mourning we have removed all guns from sale and from display in our store nearest to Newtown and suspended the sale of modern sporting rifles in all of our stores chainwide.”

“We continue to extend our deepest sympathies to those affected by this terrible tragedy.”

It is unclear how long the suspension will last.

The announcement by both Walmart and Dick’s are impacting the conversation on gun control in California, a state that already has some of the strictest law in the country.

“The Connecticut shooting is a wakeup call for all of us in America,” CA State Sen. Leland Yee said.

Yee plans to introduce a bill to close what he calls a loophole in the state’s ban on assault weapons and is considering changes to state gun laws on everything from background checks to storage regulations.

Several other California lawmakers are also planning on introducing new legislation aimed at gun control, including U.S. Sen. Dianne Feinstein.

Gene Hoffman of the Cal Guns Foundation countered, “Right now people are being reactionary about trying to pass gun control laws, but the problem is that they’ve had no real impact.”

MORE NEWS: Burlingame Shoppers Show Up for Small Business Saturday

(Copyright 2012 by CBS San Francisco. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)