Two circular loops of equal radii are placed coaxially at some separation.  The first is cut and a battery is inserted to drive a current in it.  The current changes slightly because of the variation in resistance with temperature (produced due to current in the circuit).  During this period, the two loops.

When current starts flowing in a loop heat is generated in the resistance which increases the resistivity of the resistance $\left(R=\rho \frac{l}{A}\right)$ .   Thus the resistance of the circuit increases.  This will reduce the current in that loop.  Thus from lenz law the flux passing through the other loop decreases and hence a current in same direction (as in loop 1) is produced.  Thus they both attract each other.