India, Jan. 29 -- Two constitutional courts, the Supreme Court and the Delhi high court, on Wednesday simultaneously dealt with key challenges to the Unlawful Activities (Prevention) Act (UAPA), underscoring the contentious legal landscape surrounding India's primary anti-terror law.

Even as the Delhi high court took up petitions challenging the constitutional validity of various UAPA provisions, the Supreme Court continued hearing a case questioning the central government's power to designate an organisation as a "terrorist outfit" without a prescribed procedure under the law.

A bench of justices Surya Kant and N Kotiswar Singh heard arguments in a petition filed by terror convict Saquib Abdul Hamid Nachan, challenging government notif...