Officials said Saturday that at least nine migrants drowned while attempting to cross the Rio Grande River from Mexico into the United States.

According to the US Customs and Border Patrol, the drownings occurred on Thursday when a large group attempted to cross the Rio Grande near Eagle Pass, Texas.

Thirty-seven people were rescued, but nine migrants’ bodies were discovered – three by Mexican authorities and six by US agents.

According to CBP, 53 migrants were detained on the US side of the river, while 39 were picked up by Mexican officials on the Mexican side.

There was no information provided about the migrants’ ages or nationalities.

“The search for additional possible victims continues,” CBP added.

According to a CBP official, the mass drowning appeared to be the worst in years along the Rio Grande.

According to government data, nearly 50,000 migrants were arrested in the Del Rio region of the CBP last month.

According to the city’s fire chief, Manuel Mello, the migrants were swept away by strong currents about a mile south of the International Bridge, which connects Eagle Pass to Piedras Negras, Mexico.

Mello observed that drownings had become common in the area, with as many as one occurring every day.

Recent migrant deaths have highlighted the perilous journey that hundreds of thousands of people take each year to reach the United States from Mexico.

Over 50 people died in June after being abandoned in a hot trailer in San Antonio, Texas.