The U.S. Department of Homeland Security said Saturday that Texas denied federal agents access to a section of the border as they tried to rescue three migrants who drowned.

The federal government's account came hours after U.S. Rep. Henry Cuellar said the Texas Military Department and Texas National Guard "did not allow Border Patrol agents access to rescue the migrants" Friday night. Mexican authorities recovered the bodies of a woman and two children across the border from Eagle Pass, Texas, on Saturday.

"This is a tragedy, and the state bears responsibility," Cuellar, the top Democrat on the House Appropriations Committee's Homeland Security subcommittee, said in a statement.

Fossil reveals 240 million-year-old 'dragon' Fossil reveals 240 million-year-old 'dragon'

The drownings come amid escalating tensions between Texas and the U.S. government over immigration enforcement. On Friday, the Justice Department told the U.S. Supreme Court that Texas had taken control of an area in Eagle Pass known as Shelby Park and was not allowing Border Patrol agents to enter.

The Texas Military Department said in a statement Saturday night that one of its units searched the river after being alerted to the situation by the Border Patrol, but did not find any migrants. The statement did not address the U.S. government's claim that Texas authorities "physically blocked" Border Patrol agents from entering the park at the time.

The Department of Homeland Security echoed Cuellar's account of the 911 call. In a filing with the U.S. Supreme Court on Saturday, Texas acknowledged that it had seized the city park on the border, but said the federal government had mischaracterized its actions and that it was trying to resolve any disputes over access.

"At no time did TMD security personnel along the river observe any distressed migrants, nor did TMD turn back any illegal immigrants from the U.S. during this period," the department said in the statement.