AUSTIN (KXAN) — The governor of California sent a letter Thursday asking the U.S. Department of Justice to investigate his counterparts in Texas and Florida for their efforts to transport migrants to other parts of the country.

Gov. Gavin Newsom, D-California, shared a copy of his letter to Attorney General Merrick Garland on Twitter along with a message that read, “What @GovRonDeSantis and @GregAbbott_TX are doing isn’t clever, it’s cruel.” He said the letter serves as his formal request for the Department of Justice to “begin an immediate investigation into these inhumane efforts to use kids as political pawns.”

The letter in question does not mention either Abbott or DeSantis by name, but it does call out the actions they took recently to move migrants from the Texas-Mexico border once they’re processed. “Like millions of Americans,” Newsom wrote, “I have been horrified at the images of migrants being shipped on buses and planes across the country to be used as political props. Clearly, transporting families, including children, across state lines under false pretenses is morally reprehensible, but it may also be illegal.”

DeSantis said Thursday he arranged two planes to carry immigrants to Martha’s Vineyard in Massachusetts, which escalated a tactic by Republican governors to draw attention to what they consider to be the Biden administration’s border policies. Meanwhile, Abbott also announced two buses dropped off more than 100 migrants outside Vice President Kamala Harris’ residence Thursday. Records obtained earlier this month by KXAN show Texas has spent more than $14 million sending buses of migrants to East Coast cities since August.

Newsom’s letter to the attorney general Thursday specifically raised concerns about the migrants taken to Martha’s Vineyard, mentioning a claim first reported by NPR. According to that report, three migrants told NPR a woman lured them onto the plane by saying they’d go to Boston to receive expedited work papers. Newsom said he believed this claim could violate federal law and lead to charges that include kidnapping.

KXAN reached out Thursday afternoon to see whether Gov. Abbott’s office had any comment about the Newsom request for a federal investigation. We also asked if Abbott coordinated with DeSantis on the plan to fly migrants from Texas to Massachusetts. Renae Eze, Abbott’s press secretary, did not address the Newsom letter in a statement sent to KXAN.

She instead shared that the governor’s office was not involved with DeSantis’ plans about the flights to Martha’s Vineyard. However, she said Abbott supported this move.

“Governor Abbott encourages and welcomes all his fellow governors to engage in this effort to secure the border and focus on the failing and illegal efforts of the Biden-Harris Administration to continue these reckless open border policies,” Eze said.

The White House blasted Republican governors for sending migrants to Democratic-run cities such as Martha’s Vineyard and Washington, D.C., in an attempt to make a point about immigration policy. During her briefing Thursday, Press Secretary Karine Jean-Pierre called these efforts “disrespectful to humanity.”