Riot police wielding truncheons broke up an opposition rally in a central Russian city on Saturday, beating and detaining dozens of activists. It was the second major anti-government protest by liberal and leftist forces this year to be broken up by police as the country prepares for December parliamentary elections and next year's presidential vote. President Vladimir Putin, who is constitutionally barred from running for a third consecutive term, has given strong hints he would pick a favoured successor. Opposition groups have accused the Kremlin of further consolidating control over the country's political life ahead of elections to make sure...