More than 400 illegal immigrants have been arrested in just five minutes as they tried to cross over the U.S. border in Texas.

U.S. Customs and Border Protection agents said they apprehended two large groups of illegal immigrants near El Paso in the early hours of Monday morning.

The groups were made up mostly of Central American families and unaccompanied juveniles.

More than 400 illegal immigrants (pictured above) were arrested in just five minutes as they tried to cross over the U.S. border in El Paso, Texas on Monday morning

Authorities said agents found the first group of 194 crossers at about 2.45am at the border wall just west of Bowie High School.

Just five minutes later, authorities said agents working further west encountered a second group of 252 people who crossed illegally near Downtown El Paso.

'In all, agents had already taken over 430 people into custody within the first three hours in what appears to be only the beginning of another busy day for the El Paso Sector Border Patrol,' CBP said in a statement.

Agents working in the El Paso sector say they have been averaging 570 arrests a day in the last 30 days.

'These numbers continue to stretch the resources available to the U.S. Border Patrol to deal with this influx and the challenges that come with it,' CBP said.

It comes after the number of undocumented immigrants stopped at the border with Mexico rose to more than 76,000 in February - the highest monthly level in years, the CBP said earlier this month.

Salvadoran migrants wait for a transport to arrive after turning themselves into US Border Patrol by border fence under construction in El Paso, Texas on Monday

A family from El Salvador is pictured walking to turn themselves into Border Patrol agents after crossing the Rio Grande to claim asylum in El Paso, Texas on Monday

The number of families and unaccompanied children also rose to nearly two-thirds of the total, often crossing in large groups and turning themselves in to authorities to request asylum, blunting the Trump administration's tactics aimed at curbing the flow.

At 76,103, the number of people stopped at the border or detained after crossing was up sharply from the roughly 61,000 average for the previous three months, a surprising surge for what is usually a downturn in the coldest month of the year.

It was also more than double the number of February 2018 and 3.2 times the number for February 2017, the first full month after President Donald Trump took office promising to take aim at illegal immigration.

'We are currently facing a humanitarian and national security crisis along our southwest border,' said CBP Commissioner Kevin McAleenan.

'The vast increases in families and children coming across our border, in larger groups and in more remote areas, presents a unique challenge to our operations and facilities, and those of our partners.'