Police in riot gear swarmed over the Lahore High Court building, blocking passage of about 500 extremists.
Salamat Masih, 14, and his uncle, Rehmat Masih, 40, have appealed against their conviction of writing anti-Islamic slogans on a mosque wall, a crime that carries a mandatory death sentence. "If they are freed, their lives in this country would never be safe," Hina Jilani, their defence lawyer, said.
At the appeal hearing, Ms Jilani has argued that the state has failed to give any evidence that her clients blasphemed against Islam. The offending slogans were immediately wiped off the mosque and witnesses have refused to repeat them in court, saying they are too offensive.
Even the Muslim cleric, Maulana Fazle Haq, who laid the charge, has withdrawn his complaint, said Ms Jilani. "There's no evidence. The state hasn't presented: anything, nothing."