The suspects were arrested from the south-eastern port city of Chittagong on information provided by two suspects recently arrested in the US on charges of attempting to attack establishments in different countries including a newspaper office in Denmark, a spokesman for detective branch of police said.

"We have some evidence that they (three suspects) planned to attack the US embassy and as part of the preparatory works they visited its location at Baridhara area to chalk up the detail plan," the official said.

He said the detective branch was expected to seek a court order to quiz them further in custody for the next several days. It identified the two Lashker-e-Taiba operatives as Shahidul Islam, 26, and Al Amin alias Saiful.

The HuJI man has been identified as 33-year old Mufty Harun Izhar, son of Mufty Azhar, chief of the right-wing Islami Oikya Jote party, a partner of Bangladesh Nationalist Party (BNP).

The Prothom Alo newspaper said quoting another DB source that one of the two arrested LeT operatives was an Indian national and another was a Pakistani though they claimed to be Bangladeshi nationals.

Bangladesh in the past several months has arrested three LeT operatives from different areas.