DHAKA (The Daily Star/Asia News Network) - Thirty-eight people who went abroad for jobs and studies in the last few years may have been radicalised in several countries, including Singapore, Turkey and Malaysia, according to a police investigation.

Many of them are believed to have entered Syria through Turkey to join global terror organisation Islamic State (ISIS), say sources at the police headquarters.

"Our immigration police are on alert. If any of them tries to enter the country, he will be arrested," said a police official seeking anonymity.

The records of the 38 Bangladeshis, who had gone missing in eight countries, have already been sent to the immigration police, the official added.

Of them, 13 went out of trace in Singapore, nine in Turkey, seven in Malaysia, four in the United Arab Emirates, two in Japan and one each in Qatar, Iran and Saudi Arabia, say the sources.

They are among the 51 missing people suspected to have been radicalised. The remaining 13 went missing from different parts of Bangladesh over the last couple of years.

Meanwhile, Rapid Action Battalion last night published a list of 70 missing people with their permanent addresses and pictures. Many of them are also on the police list.

The police headquarters has finalised the list of 51 after scrutinising other lists prepared independently by different law enforcement and intelligence agencies.

"The police headquarters talked to the family members of the missing people and got information that they may have been radicalised," said the police official.

Referring to some Bangladeshi students at Monash University in Malaysia, the official said they might be radicalised if the Bangladesh High Commission there doesn't keep a close watch on them.

Contacted, a senior official at the high commission said: "It is not possible for us to monitor whether any Bangladeshi student or national is getting radicalised after coming to Malaysia."

The official, however, said if they receive any information about any Bangladeshi national's involvement in militancy there, they would take necessary steps.

Two of the five Gulshan cafe attackers - Nibras Islam and Rohan Imtiaz - were students of Monash University. Another student of the university, Tawsif Hossain, also a friend of Nibras, went missing on Feb 3 after he returned to Bangladesh in November.

Tawsif is also on the list of the missing people.

Following the terror attacks at Holey Artisan Bakery in the capital's Gulshan and near Sholakia Eidgah in Kishoreganj early last month, police and other agencies took initiatives to prepare lists of missing people suspected to have been radicalised.

Junnun Sikder, a student of a top private university, Nazibullah Ansari, a marine engineer, and Mohammad Basharuzzaman, a private job holder, went traceless in Malaysia between January last year and January this year.

Besides, Rokonuddin Knondoker, a paediatrician at a government hospital in the capital, left the country along with his four family members in July last year.

He told his relatives that they would visit Malaysia and several other countries.

But they are yet to return home, and law enforcers suspect that the five-member family has been radicalised and is now in Syria.

The list also includes Tahmid Rahman Safi, the first of the three persons who appeared in the video clip allegedly released by ISIS soon after the Gulshan attack.

Tahmid, a singer and son of a former home secretary and an election commissioner, was identified from the video clip by friends and social media users.

He left home on April 23 last year for Malaysia, saying he was going on "honeymoon". But the travel agency from which he bought the air tickets told Tahmid's parents that he went to Turkey, a gateway to Syria.

Another missing person is Jubayedur Rahim, who used to play bass in a metal band. He left for Malaysia for higher studies, and went missing later.

Sajit Debnath, who converted to Islam while in Japan and took the name Saifullah Ojakir, is among the missing people. He went to Japan for higher studies on a scholarship in 2001.

Obtaining his doctorate from the Asia Pacific University there, he joined Kyoto University in Osaka as a teacher. In the meantime, he married a Japanese girl whose father was a businessman. The couple converted to Islam either in 2006 or 2007, according to police.

AKM Takiur Rahman Sifat, a barrister from Bogra, and his wife left for Saudi Arabia along with their 18-month-old daughter to perform Umrah around 16 months ago. They have been missing since then.

Completing his A-level, Sifat went to London to study law in 2006 and returned in 2011. His family members noticed a sudden change in his behaviour upon his return.

The elite Rapid Action Batallion (RAB), an elite anti-crime and anti-terrorism unit of the Bangladesh police, published a list on its official Facebook page around 10pm.

This is the third time Rab published such a list.

The number of missing people was 262 on its first list published on July 20 and 68 on the second list published on July 25.

Commander Mufti Mahmud Khan, director of Rab's legal and media wing, said they prepared the new list by incorporating four to five names and dropping that of several others who include one of the nine militants killed in the Kalyanpur operation late last month.

The list includes the names of people who have been missing since 2004.