Government officials say a lack of safety and security measures and the use of highly flammable materials in the building helped the fire spread.

The suspect, an employee with a state railway company, told authorities of his plan to attack the police facility, but gave no timeframe nor motive, reports say.

It says the raid targeted Abd-al-Hadi Mahmud al-Haji Ali and was initiated after gathering intelligence that Islamic State was plotting to kidnap officials abroad.

The al Qaeda-linked Islamist group claimed responsibility for two car bombs that exploded outside the education ministry in Somalia's capital Mogadishu, killing at least 120 people.

If convicted of the charged offences, Mirsad Hariz Adem Ramic faces a maximum penalty of 50 years in prison, a fine of US$750,000 and term of supervised release up to life.

Rights groups argue that human rights principles are at stake and Begum should answer for any crimes in her home country.