"The Islamic State is expanding its reach around the globe, and its latest focus is on Bangladesh," the report warned. 

Those words were published by Stratfor, a global intelligence company based in Austin, Texas, on April 26 — more than two months before militants killed 20 hostages in a restaurant in Dhaka, the Bangladesh capital, and ISIS claimed responsibility. 

On Thursday, extremists struck again, hurling homemade bombs at police guarding an Eid-al-Fitr prayer service to mark the end of the Muslim holy month of Ramadan in Kishoreganj district, about 90 kilometres north of Dhaka. Four people died, including one of the attackers, and more than a dozen others were injured.  

There was no immediate claim of responsibility, but after the restaurant attack, ISIS threatened more violence in Bangladesh.   

"There's definitely a groundswell of jihadism there," said Scott Stewart, Stratfor's vice-president of tactical analysis and a former special agent with the U.S. State Department.

Scott Stewart

Scott Stewart, vice-president of tactical analysis at Stratfor, says 'there's definitely a groundswell of jihadism' in Bangladesh. (Stratfor)

The Bangladeshi government has denied ISIS was responsible for either of the recent attacks, blaming them on domestic militant groups. But terrorism experts, including Stewart, disagree, saying that such groups within Bangladesh are likely affiliated with ISIS or rival organization al-Qaeda. 

ISIS has ruthlessly targeted Muslims, particularly Shia, it deems to be apostates. 

"I believe the fact that [Thursday's attack] targeted a religious gathering is a sign that it was Islamic State-related," Stewart said. "Al-Qaeda specifically prohibits such attacks in their doctrine."

The battle for control between ISIS and al-Qaeda is one factor that makes Bangladesh especially vulnerable to attacks, experts say. 

"Bangladesh is very relevant [as a target]," said Kamran Bokhari, a fellow at George Washington University's extremism program and a senior lecturer at the University of Ottawa. "It allows ISIS to say, 'Look, we're in South Asia.'"

Kamran Bokhari

Strong anti-government sentiment in Bangladesh and al-Qaeda's presence in South Asia likely contribute to the country's appeal to ISIS, says Kamran Bokhari, a fellow with George Washington University's extremism program. (Kamran Bokhari/Facebook)

"South Asia used to be al-Qaeda's turf," he added. "Al-Qaeda is now bitter that ISIS is encroaching on it."

Stewart said he's worried that both ISIS and al-Qaeda will try to surpass each other in violent attacks in Bangladesh. 

"I'm really concerned we're going to see an escalation as al-Qaeda tries to respond in kind, to keep themselves relevant," he said. "At the same time, I think that Islamic State supporters are going to want to continue to kind of add on, you know, to their gains."

Up to this point, Stewart said, attacks in Bangladesh appear to have been carried out largely by local groups who may be acting on behalf of ISIS, but likely haven't had specialized training in bombs or other weaponry. That means the attacks could have been "far more deadly" than they were, he said. 

"My largest concern is that we are going to see an infusion of more seasoned terrorists who will return to Bangladesh from Syria and Iraq," Stewart said. "That could ramp up the threat level considerably." 

Exploiting 'local grievances'

Internal strife in Bangladesh, including long-established radical groups, make it fertile ground for ISIS, Stratfor said.  

"For the Islamic State, followers of these groups represent a vast pool of potential recruits," the firm said in its April report, while acknowledging some of those local groups could also become ISIS rivals.  

Tension between the Bangladeshi government and opposition critics — some of whom were arrested in 2015, according to Human Rights Watch — feeds into the interests of ISIS, Bokhari said. 

"They are always scouting out and looking for areas where they can exploit local grievances and find allies and partners," he said. "When there is so much, you know, anti-government sentiment, that just works for ISIS."

Faiz Sobhan, research director in the foreign policy, security and countering violent extremism section of the Bangladesh Enterprise Institute, said he doesn't know definitively if ISIS has set its sights on the country, but there are reasons it might. 

Faiz Sobhan

Faiz Sobhan is a research director specializing in foreign policy, security and violent extremism at the Bangladesh Enterprise Institute. (Bangladesh Enterprise Institute)

"Bangladesh is a predominantly Muslim majority country, with the third or fourth largest Muslim population in the world," Sobhan said in an email to CBC News. "A group like ISIS may be keen to test the waters and gauge what sort of reaction it obtains in such a country."

"Their global brand resonates with many extremist groups internationally and local groups in Bangladesh may wish to jump on the ISIS bandwagon to garner more attention," he said. "As ISIS begins to suffer more battlefield losses in their heartland [Iraq and Syria], they are increasingly focusing on setting up shop in new territories."

With files from The Associated Press and Reuters