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tokens: the sources H ii 1, 2 and 6 are the extrapolated thermal flux density estimated using H emission. For the sources H ii 2 and 6, comparing the best-fitting parameter m to equations ( 1 ) and ( 2 ), we estimate the thermal freefree emission to be optically thick ( ff 1) below 0.220.03 and 0.410.05GHz, respectively. Recently, Hindson etal. ( 2016 ) in a study of Galactic H ii regions, found evidence of a turnover in the freefree spectrum typically with turnover frequencies in the range 0.31.2GHz. We estimated 8 the EM to be (1.20.3)10 5 and (4.6 1.2) 10 5 pccm 6 for H ii 2 and 6, respectively which in turn is related to the average thermal electron density n e as (Berkhuijsen, Mitra Mller 2006 ): where, f is the filling factor and h HII is the size of the H ii region along the line of sight. Assuming a typical f 5percent for the clumpy star-forming disc (Ehle Beck 1993 ) and h HII 50pc, i.e. the spatial resolution of our observations, we estimate n e to be 11 and 22cm 3 for H ii 2 and 6, respectively, which are typical values for H ii regions (Hunt Hirashita 2009 ). Deeg etal. ( 1993 ) pointed out that such values of EM and n e are necessary to explain the radio continuum spectra of star-forming blue compact dwarf galaxies. To better constrain n e and the sizes of the H ii regions, high-resolution radio continuum observations at even lower frequencies with LOFAR will be necessary. The thermal emission independently estimated using extinction-corrected H emission well represents the emission in the three H ii regions (shown as black dotted lines in Fig. 6 ). This suggests that the extinction-corrected H emission is a good tracer of the thermal freefree emission on scales below 100pc. Since, the total radio continuum emission in these regions are already consistent with 100percent thermal emission, it is difficult to estimate the contribution of the non-thermal component. We have therefore blanked these pixels in our future calculations. 4.2.2 Non-thermal bubble An interesting feature observed in the maps of and nt lies towards the south-eastern edge of IC10 marked as the non-thermal bubble in Fig. 3 . The bubble was first identified in the radio continuum observations of Yang Skillman ( 1993 ). The sharp boundary of this region is distinctly visible only in the spectral index maps (see Fig. 4 ). The total intensity emission is merged with the bright H ii region H ii 1 and does not show the bubble distinctly. In Fig. 7 , we show a zoomed-in view of the spectral index map. We mark the sharp boundary of the bubble and determine its centre to be at RA = 00 h 20 m 29 s and Dec. = 591639.5. The non-thermal bubble extends 300pc in the north-east to south-west direction and 100pc in the north-west to south-east direction. Its north-western edge, where the spectrum flattens from being non-thermal with 0.6 to thermal 0.1, is bound by GMCs as observed by Leroy etal. ( 2006 ), shown as the black circles in Fig. 7 . This suggests that the GMCs likely confine