Since September last year, about 15 suspects have been arrested for "having or trying to establish contacts" with Islamic State (IS), according to police press releases and briefings at different times.

On September 18 last year, cops arrested seven members of banned militant outfit Jama'atul Mujahideen Bangladesh (JMB) for "establishing contacts" with IS.

A police press release said the arrested were Abdullah Al Tasnim, Nayeem Ali, Sikandar Ali, Mahmud Ibn Bashar, Masum Billah, Fuad Hasan and Ali Ahmed.

Just a week later, police arrested Asif Adnan, 26, and Fazle Elahi Tanzil, 24, two suspected members of militant organisation Ansarullah Bangla Team. They were allegedly planning to go to Syria through Turkey with the help of a UK citizen of Bangladeshi origin.

According to police, the UK citizen, Samiun Rahman alias Ibn Hamdan, was in Dhaka to recruit fighters for IS, a global militant organisation based in Syria and Iraq. He was shown arrested two days later.

"From his passport we came to know that he [Samiun] went to Syria in September last year," Joint Commissioner Monirul Islam of Dhaka Metropolitan Police (DMP) then told journalists.

Samiun took part in a demonstration against Bashar al-Assad, added Monirul, also the DMP spokesperson.

On January 18 this year, detectives arrested four others -- Sakhawatul Kabir, Anwar Hossain alias Baten, Rabiul Islam and Nazrul Islam -- in the capital's Jatrabari for their suspected links with IS, also known as ISIS or ISIL.

Following their interrogation, police said Sakhawatul was working as the IS coordinator in Bangladesh.

On May 24, cops arrested a regional coordinator of JMB named Aminul Islam Beg and his associate Sakib bin Kamal. They had allegedly been trying to send operatives to Iraq and Syria from Bangladesh.

Police told the press that Aminul had so far selected 20 people from among the JMB operatives across the country; many of them were ready to leave the country to join IS.

Later on May 30, Abdullah Al Ghalib, a suspected IS recruiter and militant trainer, was detained. During interrogation, Ghalib said he was an assistant coordinator of Ansarullah Bangla Team and member of banned radical Islamist group Hizb ut-Tahrir.

Police had informed the media about all those arrests through press statements and briefings.