Updated December 1 at 11:20 a.m.

A group of top senators is asking President Obama to release more information about Russia’s involvement in the election, hinting that important details are being kept secret.

In a letter sent Tuesday and made public Wednesday, seven Democratic senators (including a Democrat-aligned Independent senator)—six members of the Senate Intelligence Committee and one member of the Senate Armed Services Committee—wrote a two-sentence letter to the White House. It read, in its entirety:

We believe there is additional information concerning the Russian Government and the U.S. election that should be declassified and released to the public. We are conveying specifics through classified channels.

The letter was led by Ron Wyden, an outspoken Democratic senator from Oregon who has long been active on technology issues. The other five signatories from the Senate Intelligence Committee included Mark Warner, who will become the committee’s next vice-chair. But the list of names had a glaring omission: Dianne Feinstein, the committee’s current vice-chair, was the only Democratic committee member who didn’t sign the letter.

A spokesperson for Feinstein said she signed onto the classified correspondence that the public letter referred to, even though her name didn’t appear on the open letter. The spokesperson did not elaborate on the discrepancy.

Just yesterday, the ranking member of the House Oversight Committee, Elijah Cummings, called for an investigation of Russia’s role in the U.S. election. Nancy Pelosi, the House Minority Leader, said she was in support of the investigation.