Moscow ? Russian police broke up anti-Kremlin protests in Moscow and St. Petersburg on Sunday, and detained more than 100 demonstrators, including several opposition leaders.

In Moscow, several hundred demonstrators gathered in a central square, defying a ban imposed by authorities. The protesters said their rally was banned in violation of the Russian constitution’s guarantee of the right to gather.

They denounced the policies of President Dmitry Medvedev and his predecessor and mentor Vladimir Putin, who continues to wield broad powers as Russia’s powerful prime minister.

Police spokesman Viktor Biryukov said about 300 people took part in the Moscow rally and about 100 were detained.

Police quickly dispersed a similar rally in St. Petersburg, detaining most of several dozen protesters who gathered on the downtown Nevsky Prospect. Some of the demonstrators were beaten with truncheons.