I'm assuming your City is the 1.3A variant with steel rims, which explains the need for hubcaps.
I'm also assuming that your hubcaps is like the one pictured above. In that case, it would be hard to remove this type of hubcap without first unscrewing the four lug nuts of the tire. Which makes me wonder how did your's manage to disattach itself?
Here in the Philippines, this hubcap can be found on the 1992-95 Civic EG 1.5 and 2003-08 City 1.3A. Try the usual "tire" places like Banawe, Evangelista, Rizal Ave, etc... or places where people trade in their old rims. Although you might have to buy 4 pcs as a set. The last resort would be any Honda dealer or ordering it from ebay (USA) (the hubcap was used on the Honda Del Sol there).