Pakistan is confirming that the younger brother of the alleged Southeast Asian terrorist Hambali was among 15 people arrested Saturday in Karachi, but authorities are still uncertain whether the brother was engaged in terrorist activities.

Pakistan's Interior Minister Faisal Saleh Hayat said Hambali's brother, Rusman Gunawan, was among a group of Indonesian and Malaysian students taken into custody Saturday.

But Mr. Hayat added that the students are still under interrogation and will be deported unless evidence surfaces that they were involved in terrorist activities. "Once we are satisfied regarding the investigation, only then we will be dealing with this aspect of deportation," he said.

Riduan Isamuddin, alias Hambali, was arrested in Thailand last month and is believed to have been a top leader of the terror network Jemaah Islamiyah, blamed for hundreds of deaths in Southeast Asia.

Rusman Gunawan had been enrolled at a Karachi religious school at the time of his arrest.