2 children dead, baby critical after attempted border crossings

Two children are dead and a baby is in critical condition after being pulled from the Rio Grande during separate attempts to cross into the United States from Mexico on Monday, officials said.

A 3-year-old boy died and a 2-month-old baby was taken to hospital in critical condition after they were pulled from the river Monday afternoon, Eagle Pass Fire Department Chief Manuel Mello said in a statement.

Mello said the children were being "brought across" the river as part of a group of migrants when the incident unfolded. It occurred around 1 p.m. local time (2 p.m. ET) on Monday, according to WOAI-TV, an NBC affiliate based in San Antonio.

Mello said Border Patrol agents were close by when the incident unfolded and assisted with the rescue. By the time fire rescue arrived on the scene, CPR was already being administered by agents, Mello said.

The 3-year-old boy was pronounced dead at the scene, while the baby boy was transferred to a San Antonio hospital, Mello said.

Mexico’s National Immigration Institute said a 5-year-old girl also drowned while attempting to cross the Rio Grande to enter Texas on Monday.

In a statement Tuesday, the institute said the child's mother had been carrying her in her arms when the force of the water snatched her daughter away.

U.S. Customs and Border Protection, which oversees the Border Patrol, said in a statement that agents with saw a woman and man on the bank of the river and an unresponsive infant in the water. The woman and infant were taken to a hospital, the agency said.

The Border Patrol agents went back to the same area and found a second child in the river. That child was later pronounced dead, the agency said.

The tragic incidents come amid a recent decline in arrests of undocumented migrants crossing the U.S. southern border after reaching an all-time high in May.

The drop comes amid an increase in U.S. assisted arrests of smugglers in Central America, according to internal briefing materials obtained by NBC News.

Agents from CBP and the Immigration and Customs Enforcement’s Homeland Security Investigations, including some operating in Central American countries, were responsible for the arrests of an average of 240 smugglers in a single week in June alone, according to the materials, prepared by the Department of Homeland Security for a White House briefing.