The two men were found as they attempted to make it across the Moroccan border into Melilla, a Spanish enclave on the North African coast. Morocco has become a major gateway into Europe for African migrants with Spain the main entry point for people for a better life in Europe as other European Union countries tighten up controls at their borders. A smuggling route through Libya to Italy has also been complicated by conflict and violence there.
Melilla, together with a second Spanish enclave, Ceuta, have the EU’s only land borders with Africa.
The migrants’ capture was caught on film and the footage published on social media by Jon Inarritu, a parliamentary senator from the Basque separatist party EH Bildu.
Mr Inarritu tweeted that without a lack of safe ways to seek asylum, attempts such as these would continue along Europe’s southern border.
Local media said the video documented the first time there had been an attempt to smuggle people inside a mattress.
Apparently shot by someone involved in the search operation, it showed two men in Guardia Civil uniform lifting two hollowed-out mattresses off the roof of a vehicle and cutting them open to reveal two men inside.
The driver of the vehicle fled to Morocco before being arrested by the authorities there.
The two migrants were said to be in good health conditions and did not require medical assistance.
UN refugee agency UNHCR said more than 6,000 migrants hade made it to Melilla and Ceuta in 2018.
In October, one African migrant died and three others were injured when around 300 stormed the border fence separating Melilla from Morocco.
The latest bid came after tech companies were accused of failing to crack down on people-smugglers using their platforms to lure migrants “to their deaths” with the promise of safe passage to Europe.
The UN said companies such as Facebook and WhatsApp were “enabling criminal activity” by traffickers who entrap victims who are unaware of the dangers they face.