Russia on Tuesday took to Twitter to denounce an earlier tweet from the US ambassador about the rough handling of activists who tried to stage a sit-in protest over Vladimir Putin’s election win. The pointed exchange between the foreign ministry and US ambassador Michael McFaul followed the arrest of more than 600 demonstrators in Moscow and Saint Petersburg on Monday after Putin’s triumph in presidential elections. All the demonstrators were released overnight but several opposition movement leaders who called for a sit-in on Moscow’s central Pushkin Square face the threat of penalties or jail terms of up to 15 days. “Troubling to watch arrests of peaceful demonstrators at Pushkin Square,” McFaul tweeted shortly after helmeted riot police moved in to break up the rally “Freedom of assembly and freedom of speech are universal values,” he said. McFaul was the architect of US President Barack Obama’s “reset” in ties with the more reform-minded outgoing President Dmitry Medvedev. But he vexed Moscow on his arrival in January by immediately meeting with top anti-Putin leaders.