WASHINGTON, Sept.12 (Xinhua) -- The number of migrant families apprehended at the U.S.-Mexico border hit new high last month, up 40 percent from July to a total of 12,774, according to data released Wednesday by the U.S. Customs and Border Patrol (CBP).

A total of 37,544 individuals were apprehended at the border in August, a hike from the 31,299 in July and 34,091 in June, the data showed.

As of August, there were still more than 500 children who were separated from their families that remained in U.S. custody, despite a July 26 deadline set by a federal judge for the reunification of all those separated at the border, a TheHill News Daily report said.

The U.S. Department of Homeland Security (DHS) said in a statement on Wednesday that the rising number of families apprehended indicates a "broken" immigration system.

"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." the DHS said.

U.S. President Donald Trump signed in June an executive order ending highly controversial "zero tolerance" policy leading to the forced separation of more than 2,500 children from their parents at the U.S. southern border.