TENS of thousands marched down Mexico City’s main boulevard on Wednesday, protesting at the unsolved disappearance of 43 Guerrero state students and demanding the government find them.

Relatives of the missing students carried hand-painted portraits of their children as they joined the marchers, some of whom demanded the resignation of President Enrique Pena Nieto.

The largely young crowd carried Mexican flags with black mourning bands replacing the red and green stripes, counting off the numbers from one to 43.

Protesters also chanted: “They took them away alive and alive we want them back.”

In Chilpancingo, the capital of Guerrero, groups of protesters angry about the government’s inability to find the missing used hijacked lorries to block all three main roads leading into the city for several hours.

Despite the protesters’ slogan, there seems little hope of finding alive any of the 43 students at the Ayotzinapa rural teachers’ college.

Prosecutors believe that police arrested them after a confrontation in the city of Iguala on September 26 and handed them over to a drugs gang, some members of which have admitted killing the youths.

Authorities have turned up dozens of corpses in a number of mass graves around Iguala, but none has included any of the missing 43 student teachers.

Mexico’s government estimates that 22,322 people have disappeared since the start of the country’s drug war in late 2006.

The 43 students have received more attention than the others, partly because of the role played by corrupt police in their fate.