Most of the children rescued have lost their livelihoods in the devastating earthquake on April 25.
The 7.8-magnitude quake, which killed more than 8,600 people, devastated rural areas, with hundreds of thousands losing their homes and possessions.
"We have rescued 26 children from the clutches of human traffickers in the past 20 days and sent them to rehabilitation centres," said Sanjeev Kumar, a senior labour official in Bihar's East Champaran district.
According to media reports, The parents of the children, mostly migrant labourers, were asked to allow their children, between the ages of eight and 14, to travel with the traffickers, who promised to give them well-paid jobs in comfortable conditions.
Four traffickers were detained by the police. Two Nepali children were also intercepted.
The border between India and Nepal is 1,088 miles (1,751km) long and only lightly patrolled.