  The properties of 5D gravitational flux tubes are considered. With the cross
section and 5th dimension in the Planck region such tubes can be considered as
string-like objects, namely $\Delta-$strings. A model of attachment of
$\Delta-$string to a spacetime is offered. It is shown that the attachment
point is a model of an electric charge for an observer living in the spacetime.
Magnetic charges are forbidden in this model.
