We describe radial-velocity time series obtained by HARPS on the 3.60 m telescope in La Silla (ESO, Chile) over ten years and report the discovery of five new giant exoplanets in distant orbits; these new planets orbit the stars HD 564, HD 30669, HD 108341, and BD -114672. Their periods range from 492 to 1684 days, semi-major axes range from 1.2 to 2.69 AU, and eccentricities range from 0 to 0.85. Their minimum mass ranges from 0.33 to 3.5 M sub(Jup). We also refine the parameters of two planets announced previously around HD 113538, based on a longer series of measurements. The planets have a period of 663 + or - 8 and 1818 + or - 25 days, orbital eccentricities of 0.14 + or - 0.08 and 0.20 + or - 0.04, and minimum masses of 0.36 + or - 0.04 and 0.93 + or -0.06 M sub(Jup). Finally, we report the discovery of a new hot-Jupiter planet around an active star, HD 103720; the planet has a period of 4.5557 + or - 0.0001 days and a minimum mass of 0.62 + or - 0.025 M sub(Jup). We discuss the fundamental parameters of these systems and limitations due to stellar activity in quiet stars with typical 2 ms super(-1) radial velocity precision.