Police said they killed nine suspected Islamic militants, including one identified as an American, during a raid on their den in Bangladesh's capital Tuesday.
The American was identified as 24-year-old Shazad Rouf, a master's student in business administration at North South University in Dhaka. Police said Rouf was born in Bangladesh but held U.S. citizenship.
Investigators said Rouf and a group of several other jihadis had been plotting a terror attack, but the target was unclear. Rouf narrowly escaped a police raid in February that ended with three of his friends in handcuffs, The New York Times reported.
Rouf had moved with his family to the Chicago suburb of Elmhurst in 1999, then moved to the San Francisco area, his father, Tauheed, told The Washington Post. The family reportedly moved back to Bangladesh in 2009.
The father said he had no sign his son was becoming radicalized. "Maybe it was my inability to understand, but we never got any indication."
His family reportedly lost contact with him around the time of the raid. Rouf's father filed a missing-person report with police on February 6, the Times added.
Police arrested one suspect in Tuesday's raid, Police Chief A.K.M. Shahidul Hoque told reporters. Officers said they recovered grenades, revolvers, explosives, knives and two black flags in the raid.
The arrested suspect was being treated at a hospital for bullet wounds. The chief said the raid unfolded in Dhaka's Kalyanpur area.
A resident of the building who identified himself by one name, Anik, told The Associated Press residents first heard gunshots after midnight and took cover by lying on the floor of the fifth floor of the building. The suspects lived on the fourth floor.
"We heard 'Allahu akbar' coming from the fourth floor as the firing began," he said, using the Arabic phrase for "God is great."
"It was a terrible situation," he said.
The suspects had rented the apartment very recently, said Mizanur Rahman, a police sub-inspector in the area.
Hoque said officials were still investigating to see whether the militants belonged to a larger terrorist organization, but their clothing and other evidence showed they likely belonged to local banned group Jumatul Mujahedeen Bangladesh, or JMB. The group is blamed for a July 1 attack on a restaurant in Dhaka's Gulshan diplomatic area, which killed 20 people, some of them Italian and Japanese.
"It will take a few hours to have a clear idea, but we have found them clad in black dress ... suggesting they belong to the same group involved in the attack in Gulshan," Hoque said.
The Islamic State terror group claimed responsibility for the July 1 attack and for many other recent attacks on atheist bloggers, foreigners and minority groups, but authorities have rejected the claims, saying there are no signs of the group having any existence in the country. Instead, the government says local militant groups including the JMB are behind such attacks.
The Associated Press contributed to this report.