WASHINGTON/NEW YORK (Reuters) - Government investigators warned of dangerous overcrowding at more migrant facilities on the southwest U.S. border, publishing photos on Tuesday of packed cells in Texas’ Rio Grande Valley where some children have no access to showers or hot meals.

A report issued by investigators for the Department of Homeland Security said supervisors raised concerns for the health and safety of detainees and agents, warning that the overcrowding represented a “ticking time bomb.”

The DHS watchdog issued the report after June visits to five U.S. Customs and Border Protection (CBP) agency facilities in the Rio Grande Valley (RGV) sector, the busiest area of the border for migrant arrests.

It came as President Donald Trump’s administration pushed back against criticism of its migrant detention centers on the U.S.-Mexico border.

Conditions at the centers have been a flashpoint since May when the watchdog warned of similar conditions at facilities in the El Paso, Texas sector, west of the Rio Grande Valley, with migrants held for weeks instead of days, and adults kept in cells with standing room only.

Security incidents among men at RGV facilities included detainees clogging toilets in order to be released from cells, migrants refusing to return to cells, and special operations teams brought in to show that Border Patrol was prepared to use force, the report on Tuesday said.

Migrants banged on cell windows and shouted when investigators visited. Most single adults had not had a shower despite several being held as long as a month. One photo showed a man in a cell with 88 men, that was built to hold 41, holding a message reading: “Help 40 Day(s) Here.”

The watchdog’s report recommended CBP accelerate transfer of single adults to Immigration and Customs Enforcement (ICE), the agency responsible for long-term migrant detention.

Border Patrol stations have been overwhelmed after migrant apprehensions hit a 13-year high in May during a surge in Central American families.

Migrant flows have since dropped after Mexico deployed thousands of militarized police as part of a deal with the United States to avoid U.S. tariffs on Mexican goods.

Border-wide apprehensions fell 30% to 100,037 in June from 144,278 in May, including people who appeared at border crossings and were deemed inadmissible, the Mexican government said on Tuesday, citing U.S. Customs and Border Protection data.[nL2N24400D]

DRINK OUT OF TOILETS

Members of a congressional group visiting facilities in El Paso on Monday said migrants were being kept in deplorable conditions.

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The delegation had been told to surrender its phones ahead of the tour, but Democratic U.S. Representative Joaquin Castro smuggled a device into a Border Patrol station and took video of women in a cramped cell.

Some said they had been held for 50 days, some separated from children, denied showers for up to 15 days and in some cases, medication, Castro tweeted.

According to Democratic U.S. Representative Alexandria Ocasio-Cortez, women were told to drink out of a toilet.

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“I don’t know what Alexandria Ocasio-Cortez is talking about,” White House spokesman Hogan Gidley said in an interview with Fox Business Network, calling members of CBP “some of the bravest men and women on the planet.”

“They provided three meals a day to people who are here illegally and unlawfully, two snacks in between,” Gidley said.

Trump has made a crackdown on illegal immigration a centrepiece of his domestic policy agenda and 2020 re-election bid. But his efforts to build a wall on the southern border have been blocked in Congress, and he was forced last year to backtrack after his “zero tolerance” border policy of separating migrant children from their parents provoked widespread outrage.

A federal judge in Seattle on Tuesday blocked a Trump administration policy that would have kept thousands of asylum seekers in custody while they pursued their cases.[nL2N24400K]

The American Civil Liberties Union, and other immigrant rights groups, sued the government to stop the policy of denying bond hearings to asylum seekers.

U.S. District Judge Marsha Pechman ruled that people detained after entering the country to seek asylum were entitled to such hearings.

In New York, several hundred people gathered on Tuesday to demonstrate against the Trump administration’s treatment of migrants, part of a planned nationwide day of protests by rights groups targeting members of the U.S. Congress.

The demonstrations were fuelled by fears the Trump administration is preparing a roundup of immigrants who are in the country illegally. Trump last month delayed the raids by two weeks.