After eight hours of questioning the Commonwealth Games Chief Suresh Kalmadi yesterday, the CBI has raided about 10 premises in the National Capital Region. Sources in the CBI said it has registered a fresh FIR in connection with its probe into the alleged multi-crore Commonwealth Games overlays scam.Official sources said the CBI registered the FIR, the fourth in the case, yesterday in connection with the overlays contracts given out to four firms. The sources said the CBI raids started early in the morning today and are focussed on four companies, which had acted as the Indian arm for the same number of international firms. The overlays contracts are already under the scanner of both the Income Tax Department and the Enforcement Directorate.The CBI had earlier registered three FIRs for alleged corruption in projects and events in the run up to the sporting extravaganza.