Hopes that a Christian girl in Pakistan accused of blasphemy would be released on bail have been dashed, as the case, which has attracted worldwide condemnation, became bogged down in legal wrangling.

A judge at an Islamabad court deferred the bail hearing of Rimsha Masih until Monday after it emerged that two separate sets of lawyers were attempting to defend her against charges of burning sacred Islamic texts – a crime in Pakistan that can be punished by death.

The dispute allowed lawyers from the other side to challenge the authenticity of the bail application.

In court for the short hearing was Rimsha's accuser, Malik Amad, who claims to have spotted her last month walking near her house in a slum area on the outskirts of Islamabad carrying ashes, which it is claimed included burned pages with verses from the Qu'ran.

The desecration of the holy book is regarded as a particularly grave form of blasphemy and can easily spark violent public reactions in Pakistan.

Also present was a local mullah, Hafiz Mohammed Khalid Chishti, who has called for the law to be followed to its conclusion, even if that means the girl is executed. As with other members of the Muslim community in the area, he has rejected claims that Rimsha has Down's syndrome or is mentally impaired.

Central to the case is the age of Rimsha and whether her case should be heard by the more lenient juvenile justice system. In their bail application, the defence lawyers argue she is 13. A medical report prepared earlier in the week said she was 14 with a lower mental age, although the court has not yet decided to accept the report.

Chishti has also been at the forefront of a dispute between the two communities, complaining that Christians in the area were holding noisy services in their churches. He welcomed the departure of nearly all the Christians from the Islamabad neighbourhood in the tense days after Rimsha's arrest, but about half of the families have now returned to the area.

"They have returned, but they are still living in fear," said Shamaun Alfred Gill, spokesman for the All Pakistan Minorities Alliance.

With the plight of Rimsha attracting international condemnation the case has brought more attention to the treatment of Pakistan's minorities.

Murderous attacks against members of the Shia sect are on the rise, particularly in the restive province of Baluchistan. On Saturday the death toll increased again, with seven people gunned down in two separate incidents near Quetta, the provincial capital.

Complaints by Hindus have also been mounting in recent months, with families claiming their daughters have been forcibly kidnapped, converted to Islam and then married to their abductors. Parties of Hindu pilgrims were recently detained at the border with India after the government feared they intended to claim asylum and never return.

Christians, as well as Muslims, have long suffered at the hands of the country's blasphemy laws. For years rights campaigners have demonstrated how the laws, which ultimately stem from British colonial rule, have been used by individuals to settle scores and economic disputes, often on the basis of flimsy evidence.

Despite several ludicrous cases, including the jailing of people for allegedly touching a Qu'ran with dirty hands, public figures are loath to try to reform the system. Two politicians have been assassinated by religious hardliners for criticising the laws.

Unusually, Rimsha has attracted support from some heavyweight Islamic clerics, many of them regarded as hardliners. A statement published earlier in the week by Rimsha's father, Misrek Masih, credited the support by the clerics to the amount of international attention the case was getting, which had also forced the attention of the president, Asif Ali Zardari.

In an online petition, Masih urged supporters to "keep up the global outcry on my daughter's case". The uproar, however, has bemused Rao Abdur Raheem a lawyer for the prosecution, who said Muslims could "take the law into their own hands" if Rimsha was not convicted.

On Saturday he blamed foreign powers for whipping up support. "I don't understand the interest of the international community because there are so many innocent people in Pakistan being murdered," he said. "A single drone attack and hundreds of people die. What is the difference between Rimsha and these innocent people?"

Another member of the prosecution team said that even if Rimsha was acquitted she would never be able to return with her family to her home. "She would not stay in Pakistan," said Mohammad Izzat Khan. "She would be in America within a week."