A Franson-type test of Bell inequalities by photons 10.9 km apart is p
resented. Energy-time entangled photon pairs are measured using two-ch
annel analyzers, leading to a violation of the inequalities by 16 stan
dard deviations without subtracting accidental coincidences. Subtracti
ng them, a two-photon interference visibility of 95.5% is observed, de
monstrating that distances up to 10 km have no significant effect on e
ntanglement. This sets quantum cryptography with photon pairs as a pra
ctical competitor to the schemes based on weak pulses. [S0031-9007(98)
07478-X].