Some military recruitment centers 'are no safer than a shoe store in a shopping mall'

The shooting that killed five Marines at two military facilities in Chattanooga, Tennessee has prompted questions about how best to protect these centers from potential attacks.

Rand Corporation terrorism and security expert, Brian Michael Jenkins told the New York Times Friday that facilities like the military recruiting center targeted by a 24-year-old gunman Thursday are deemed "soft targets," and are "no more protected than a shoe store in a shopping mall."

Jenkins says the people working there "are in uniform, but unarmed."

That vulnerability has led the governors of at least four states to change that. Oklahoma governor, Mary Fallin (R) issued an executive order Friday allowing personnel to arm themselves at military facilities in the state, KOKH-TV reports.

"It is unfathomable that [unarmed Marines] should be vulnerable for attack in our own communities," Fallin said in a statement Friday.

And on Saturday, the governors of Texas, Florida and Indiana authorized similar orders for National Guard members and recruiting offices.

Six National Guard storefronts in Florida will be relocated to armories.

Florida governor Rick Scott (R) was cited in a Reuters report, saying "Guard members who do not carry weapons should get them and obtain expedited concealed weapon permits, if necessary."

Speaking about the fatal attacks in Chattanooga, Texas governor Greg Abbott (R) said in a news release, "our military personnel must have the ability to defend themselves against these type of attacks on our own soil."

FBI spokesman Ed Reinhold said the shooting in Chattanooga is being investigated "as an act of terrorism until we can confirm it is not."

It's another in a string of similar attacks against military outposts in the US since 2009. In that period, three different shootings at military installations on US soil have left 26 people dead.

Not all of the attacks, however, were the result of homegrown extremism - but such motives have been on the rise, according to analysis from New America, a nonpartisan think tank.

In a July report, the organization found 313 individuals have been charged with jihadist extremism within the United States since 2001.