Republicans are demanding access to American survivors of the Sept. 11 attack on the U.S. mission in Benghazi from new Secretary of State John Kerry, Julian Pecquet of The Hill reports.

In a letter sent to Kerry, Rep. Frank Wolf (R-Va.) says a source told him that "as many as 30 Americans" were wounded during the two attacks — the first of which took place at the diplomatic mission and was followed by a second at a secret CIA annex about a mile away.

The first attack took the lives of Ambassador Chris Stevens and Information Management Officer (IMO) Sean Smith while CIA contractors Tyrone Woods and Glen Doherty were killed in the second after rescuing Americans from the diplomatic building and bringing them a secret CAI annex.

The U.S. effort in Benghazi "was at its heart a CIA operation," and only seven of the more than 30 American personnel working there were from the State Department, according to a November story in The Wall Street Journal.

Wolf's letter states that "a reliable source" recently told him that as many as seven wounded American personnel, including State Department employees, are currently being treated at Walter Reed National Military Medical Center.

Pecquet notes that Kerry confirmed last week that he's visited a survivor at Walter Reed.

The letter requests the contact information for each of the State Department survivors so that Congress "can make appropriate arrangements."

Speaking to one of these State Department employees would provide Congress with first-hand information they've been asking about for months.

Rep. Dana Rohrabacher (R-Calif.), chairman of the House Foreign Affairs panel on emerging threats, wrote a letter of his own to Kerry in which she slammed the State Department for "stonewalling a legitimate request for information" in regards to interviewing survivors.

Last weekend Sen. Lindsey Graham (R-S.C.) told Fox News that Sens. John McCain (R-Ariz.) and Kelly Ayotte (R-N.H.) will join him a writing a letter "asking [Kerry] to make the survivors available to the Congress."