All Progressives Congress thugs on Friday burnt down the state secretariat of the Peoples Democratic Party in the Bayelsa State capital, Yenagoa, and smashed vehicles at the residence of the Governor-elect, Duoye Diri.
They also damaged psrts of the building.
The attacks came hours after the Independent National Electoral Commission issued a Certificate of Return to Diri at its Yenagoa office.
APC supporters also took to the streets in protest at the ouster of the former Governor-elect David Lyon.
The inauguration of Diri was being awaited at press-time.