The incident came amid alleged moves by some lawmakers to impeach Governor Siminalayi Fubara.
It was gathered that some suspected arsonists threw an explosive into the complex around 9:25pm, causing a fire in the building.
Though the spokesperson for the state police command, Grace Iringe-Koko, could not be reached on her mobile, a senior police officer confirmed the incident to our correspondent.
Our correspondent gathered that some properties inside the chamber were destroyed.
The police officer, who pleaded anonymity due to the sensitive nature of the incident, claimed it was politically motivated.
“Yes it is true. The fire occurred around 9:30pm or so. But as we speak, it (the fire) has been put out by firefighters who arrived at the scene just in time. I think it has to do with politics,” he stated.
Our correspondent gathered that arrangements have been concluded by some lawmakers in the state legislature to first impeach the House leader, Eddison Ehie, to pave the way for Fubara’s removal.
The House leader is said to have been blocking moves aimed at removing Fubara.
Our reporter, who visited the Assembly at about 10:30 pm, reports that the police and other security operatives had taken over the complex, as about 17 security trucks and one Armoured Personnel Carrier were stationed at the entrance and surroundings.