title: Russian riot police detain opposition protesters in St Petersburg: Reuters witness
text: ST PETERSBURG (Reuters) - Russian riot police detained at least 10 opposition protesters on Saturday in central St Petersburg as hundreds of anti-Kremlin activists marched towards the city s main street, a Reuters witness said. Police across Russia detained more than 100 opposition activists earlier on Saturday for taking part in a wave of protests in support of jailed opposition leader Alexei Navalny ahead of a presidential election in March. The authorities said most of the protests were illegal because they had not been officially approved beforehand.   