Most of them are madrassah students and Imams of mosques, Kushtia Police Superintendent Abdus Salam told this correspondent yesterday.

The SP said police vigilance has been increased in Kshtia to locate them and watch their movement. Their leader is from Tangail, he said.

Police said the 13 alleged Hizbut Towhid members arrested during Tuesday's clashes at Poradaha railway station are being interrogated.

Police only said they have gathered some evidence on

"their Jihad (holy war)" but declined to elaborate in the interest of the investigation.

At least 43 people were arrested during the clash between alleged Hizbut Towhid members and madrassah students at the station. Police also recovered some leaflets distributed by the militants, which called for Jihad.

The 13 will be produced before court today. Police said they will seek their remand for interrogation.

Meanwhile, leaders and activists of some Islamic parties including Islami Shasantantra Andolon, Islami Ain Bastabaion Committee, Khilafat Majlish brought out a procession and landed over a memorandum to the Deputy Commissioner on Thursday demanding action against Hizbul Towhid, terming it a "terrorist organisation".

According to other sources, Hizbut Towhid has "well-equipped centres" in Kushtia, Jhenidah, Meherpur and some other southern districts.

Thirty-four Hizbut men were arrested in Kaliganj in Jhenidah in July.

Police claimed that its Kushtia district leaders Mahbubur Rahman and Nahid Islam have "close links" with a component party of the ruling four-party alliance. Arrested last month in a theft case, both are now on bail.