EL ALTO, Bolivia Erick Callejas may be just 10 years old - and a lot shorter than the other participants on the soccer pitch - but he has no qualms enforcing the rules as one of the few referees his age.

In high-altitude El Alto, Bolivia's second-largest city and neighbor to capital La Paz, Callejas can be found on weekends blowing his whistle and calling the shots at local games, inspired by his referee father Ramiro.

"On Saturdays and Sundays I go out to referee with my little colleague, my son, Erick," Ramiro said. "I am very proud, I'm filled with emotion because refereeing runs in his blood."

Callejas refereed his first match in a women's league after his dad signed him up for the job.

"There was a women's championship and (the coordinator) asked if I could referee and I said yes."

So far, he seems to be impressing his elders with his style. Player Beimar Tancara says Callejas has a natural talent.

"You can tell he has that character. He runs. He moves. He is not intimidated by people, even if the public shouts," Tancara said.

"I think he was born to be a referee. He is very talented. I like his refereeing."

For now, Callejas is umpiring games on sandy pitches in the community league, watched closely from the sidelines by his mother and coached by his father.

But he has big hopes to one day take his talents international.

"My dream is to referee the Bolivian Derby, to be a FIFA referee so I can go to the World Cup, America Cup, Liberators Cup and the Champions League," Callejas said.

(Reporting by Monica Machicao, Sergio Limachi, Santiago Limachi; Writing by Isabel Woodford; Editing by Lincoln Feast)