We present magnetization measurements on lightly doped La_1-xSr_xMnO₃ single crystals with 0.06≤x ≤0.15 in external fields up to 14 T at temperatures between 4.2 and 180 K. In contrast to the ferromagnetic behavior which is found for x≥0.11, the samples with x=0.06 and x=0.09 exhibit a pronounced hysteresis and a constant high-field susceptibility. By analyzing this particular behavior we can rule out a phase separation into ferromagnetic and antiferromagnetic regions. On the other hand, a model of a canted antiferromagnet can account for the main experimental features.