  Electromagnetic transitions from deformed structures based on $\alpha$
configurations or on heavier clusters are discussed, drawing the link between
multiparticle-multihole excited bands and cluster structures. Enhanced E2 and
E1 transitions are reviewed in the light nuclei, $^8$Be, $^{10}$Be, $^{12}$C,
$^{16}$O, $^{18}$O and heavier ones like $^{212}$Po. Connections between
cluster structures and superdeformed configurations in $^{36}$Ar and $^{40}$Ca
are discussed. What the cluster states based on heavier substructures like
$^{12}$C and $^{16}$O are concerned, recent results on the resonant radiative
capture reaction $^{12}$C($^{16}$O,$\gamma$)$^{28}$Si are presented, in
particular the strong decay mode involving the feeding of low-lying $^{28}$Si
1$^+$ and 2$^+$ T=1 states by enhanced M1 isovector transitions.
