Detectives arrested a 19-year-old man in Sadar upazila of Jashore on Thursday night for his alleged involvement in extremist activities.

Tahsin Islam, son of Ohidul Islam of Kismat Noapara, was picked up from his house during a raid around 9:00pm, according to the Detective Branch (DB) of police.

A machete, some wires and several electronic devices were seized from his room during the operation, it said.

Later, he was handed over to the Counter Terrorism and Transnational Crime (CTTC) unit of Dhaka Metropolitan Police for further investigation.

Additional Superintendent of Police (Crime and Ops) Mirajul Islam said Tahsin was arrested based on information obtained during the investigation of a case filed with the CTTC unit in Dhaka.

Police also said Tahsin is an accused in a previously filed robbery case.

During preliminary interrogation, Tahsin allegedly admitted to having links with the much-talked-about Fatah Combat System (FCS), police said.

However, based on the information he provided, investigators have not found any evidence of active members or organisational activities of the group in Jashore, according to the police official.

After completing the necessary legal formalities, Tahsin was handed over to the CTTC.

Earlier, on July 5, the CTTC detained six young men in Dhaka's Jatrabari area on suspicion of assembling to carry out extremist activities.

Investigators said the operation led to information about the activities of a wider network.

Law enforcement agencies have alleged that Fatah Combat System uses martial arts training as a cover to radicalise and recruit young people into extremist activities.