Islamabad: Pakistan security agencies on September 23 raided a religious seminary in the port city of Karachi and arrested four foreign students, officials said.

The number of arrested foreign religious students in a week has increased to 21 after the new arrests.

A total of 15 Malaysian and Indonesian students of a religious school were arrested in Karachi on September 20.

The students are being interrogated in Karachi. One of the detained was believed to be Rusman Gunawan, the younger brother of Indonesian militant Hambali, al-Qaida's alleged top agent in South Asia.

Officials of a government agency arrived in Jamia Abu Bakr in Gulshan Iqbal block-5 on September 22 night.

They questioned four Indonesian students David Pintrio, Abdullah, Ilham Sobandi and Anwar Siddiqui and took the students, the foreign students affairs' in-charge of the seminary said.

These students had got admission in the Jamia in July 2003, he said.

Meanwhile, Pakistan's Interior Minister Faisal Saleh Hayyat said security agents had been watching for weeks before arresting him.

Gunawan was being interrogated at an undisclosed location in Pakistan, Hayyat said.

"Hambali's brother was under surveillance for weeks," Hayat said. "Perhaps he was not aware that he was being watched.

"We are interrogating Gunawan to determine if he had any plan to harm Western interest. I think he will remain in our custody for some time," he said.

PTI