Arrests of immigrant families who cross the U.S. border rose 38 percent in August, despite the Trump administration's practice of separating children from parents to deter illegal crossings.

The number suggests that the effects of the immigration crackdown have failed to discourage to families who are largely fleeing in countries like El Salvador, Honduras and Guatemala when they heard north.

About 12,800 family members crossed in August, or about 3,500 more than the 9,247 in July, according to statistics released Wednesday by the Department of Homeland Security.

It is the highest August ever in what has already been a record year for the apprehension of families at the U.S.-Mexico border. The majority of these migrants come from Central America.

"This means no one is being deterred," said Adam Isacson, a security analyst at the Washington Office on Latin America. "And whatever is pushing them out of Central America is even stronger."

Jennifer Podkul, the policy director for the legal nonprofit Kids in Need of Defense, said, "This jump is consistent with deteriorating conditions in Central America as well as annual migratory patterns. It also shows deterrence methods like family separation do not work in a real refugee crisis."

But Sarah Pierce, a lawyer and analyst with the Migration Policy Institute, said the 38 percent rise in family member apprehensions was the largest in 5 years in what is often a seasonal increase from July to August.

Pierce took a contrary view on whether it showed family separations failed to deter.

"It might be showing a bit of a surge because of the end of family separations," Pierce said.

Pierce also noted that overall apprehensions were up 20 percent.

The Trump administration has repeatedly said the surge of families led them to adopt the zero tolerance policies that resulted in the separation of about 2,600 children from their parents. On June 20, President Trump ended the practice.

Advocates for the immigrant families say many of them have a lawful right to cross into the U.S. if because they are seeking asylum based on the conditions in their home countries. They note the high levels of violence in El Salvador, Honduras and Guatemala, the three countries that are sending the majority of migrants north.

DHS press secretary Tyler Q. Houlton disputed that in a statement Wednesday as the numbers were released. Houlton said August numbers "show a clear indicator that the migration flows are responding to gaps in our nation's legal framework.... Smugglers and traffickers understand our broken immigration laws better than most and know that if a family unit illegally enters the U.S. they are likely to be released into the interior."

DHS is required to release families entering the country illegally within 20 days of apprehension,

the press secretary said in reference to the 1997 Flores court settlement.

As part of the overall crackdown on immigration, the Trump administration last week moved again to change the conditions agreed to in the Flores case, which set detention standards for migrant children.

"We know that the vast majority of family units who have been released, despite having no right to remain in any legal status, fail to ever depart or be removed," Houlton said. "Through the third quarter of FY 2018, only 1.4 percent of family units have been repatriated to their home country from noncontiguous countries such as El Salvador, Guatemala, and Honduras."

Overall border apprehensions remain significantly lower than in their peak year of 2000, when 1.6 million were apprehended. For the 11 months of this fiscal year, there were about 355,000 apprehensions, according to U.S. Customs and Border Protection, a DHS agency.