LAHORE (AFP) - Jamaatud Daawa, one of country's biggest charities, said Friday it would mount a legal challenge to the decision to close it down after the United Nations listed it as a terrorist organisation. Pakistan moved Thursday to shut down Jamaatud Daawa, freezing its assets and placing its leader under house arrest, after the United Nations said it was a front for the banned militant group accused of planning the Mumbai attacks. Mohammad Talha Saeed, the son of the charity's leader, condemned the move Friday, saying Jamaatud Daawa was engaged in relief work. "Daawa was doing welfare work across Pakistan, but the relief work has been stopped," he told the congregation during Friday prayers at a mosque run by the organisation. "There is no moral or legal justification for this action." Later, Saeed told AFP the group would "go to competent courts for our rights" and would resort to the International Court of Justice if necessary. Around 2,000 people attended Friday prayers at Jamaatud Daawa's main mosque in Lahore. Many condemned the decision to close one of country's biggest charities, which has denied allegations it is a cover for the banned group Lashkar-e-Taiba. "I do not understand why the government has stopped the blood bank services, the relief and free health services," said Muhammad Shoaid, 24. "The Pakistani government should take a good look at Jamaat's relief and rehabilitation work and then allow it to continue." Public relations worker Ali Akbar, 26, said Jamaat-ud-Daawa's closure had "badly affected relief and rehabilitation work being carried out for the sick," while student Ayesha Kalee, 19, said she had been "shocked and saddened" by the move.