Four Republican senators have signed onto a letter to the Defense Department’s inspector general (IG) expressing “grave concern” over Ukraine’s sudden loss of access to intelligence-sharing and high-speed Starlink data, which it needs to intercept Russian drones, and asked him to investigate whether senior Defense officials played a role. “We urgently request an Inspector General investigation into these incidents, including whether actions or decisions by the Department of Defense or its contractors contributed to these dangerous circumstances,” the Republican senators wrote in a bipartisan letter that was spearheaded by Sen. Jeanne Shaheen (D-N.H.), the ranking member of the Senate Foreign Relations Committee.

Republican Sens. Thom Tillis (N.C.), Susan Collins (Maine), Lisa Murkowski (Alaska) and John Cornyn (Texas) signed the letter to Platte Moring, the Pentagon’s IG. They asked whether “any Department of Defense or other U.S. government officials directed, authorized, approved or had advance knowledge of changes to intelligence-sharing arrangements, warnings capabilities, or Starlink and Starshield services affecting Ukraine.”

Collins, a senior member of the Senate Intelligence Committee, is facing a competitive race for re-election this year in Maine, a state that Vice President Harris carried in the last election. Cornyn, who is retiring at the end of the year, is also a member of the Intelligence panel. Democratic Sens. Dick Durbin (Ill.), Richard Blumenthal (Conn.), Chris Coons (Del.) and Jack Reed (R.I.), the ranking member of the Senate Armed Services Committee, also signed the letter.

“We write with grave concern regarding reported disruptions to critical U.S.-supported communications and intelligence-sharing capabilities in Ukraine that have endangered American personnel and potentially compromised Ukraine’s ability to defend against Russian missile and drone attacks,” the senators wrote.

They cited reports that restrictions imposed on data flowing through SpaceX’s Starlink terminals earlier this week disrupted the communications network supporting Ukraine’s unmanned aerial vehicles and fixed-wing and rotary-wing aircraft. They noted that the Ukrainian military on Oct. 14 reported restrictions to craft flying faster than 63 mph and that SpaceX reportedly acknowledged a service restriction on vehicles flying faster than 100 mph. “These restrictions reportedly degraded Ukraine’s ability to conduct defensive operations against Russian drone and missile attacks on civilian infrastructure,” the senators wrote.

They also said they were “deeply concerned” by reports of disruptions affecting intelligence-sharing and threat-warning capabilities used by American personnel based in Ukraine. They said that some American personnel experienced “serious difficulties reaching safety during Russian air raids” because of the so-called “glitches” and asked whether the disruptions were caused by changes in U.S. government policy. “Given the potentially deadly consequences, these incidents require immediate investigation,” the senators wrote.

Ukrainian officials on Wednesday said that the disruptions in Ukrainian access to Starlink- and Starshield-provided data stemmed from decisions made in Washington. Starshield is the military version of Starlink, which is owned by SpaceX, the commercial space company founded and led by Elon Musk. Musk on Wednesday deflected blame over Ukraine losing critical access to Starshield by noting in a post on social media that the Pentagon operates its communications systems. Musk explained that Starshield systems “are owned and controlled by the U.S. government” and emphasized “any limits on speed or usage are decided by the U.S. military and ultimately POTUS,” referring to the president of the United States.

The Republican and Democratic senators who wrote to the Pentagon IG warned that “any restrictions” on Ukraine’s ability to access Starshield data to operate its drones and military aircraft “raise serious questions about the Department of Defense’s contractual oversight and its responsibility to ensure continuity of essential services.”They asked Moring to “immediately investigate” whether disruptions to intelligence sharing, threat warnings and other U.S.-supported capabilities made it tougher for American diplomatic, military and security personnel to reach shelter during Russian attacks.

They also want Moring to find out whether intelligence-sharing disruptions and Starlink restrictions are connected and whether they were the result of “deliberate policy decisions.”They asked the GI to initiate an immediate investigation and provide written confirmation of its status no later than Nov. 1, two days before Election Day.