  We successfully isolated the $^{17}$O NMR signals at the planar sites in
La$_{1.885}$Sr$_{0.115}$CuO$_4$ ($T_{c}=30$ K) by applying an external magnetic
field along the Cu-O-Cu bond direction of a single crystal. We demonstrate that
charge order enhances incommensurate Cu spin fluctuations below $T_{charge}
\simeq 80$ K.
