Moscow—Nearly 1,400 people were detained in a violent police crackdown on opposition protesters in Moscow over the weekend, as riot officers in body armor clashed with protesters outraged over alleged government corruption.

The spark for Saturday's protests in Moscow was the decision by election authorities to ban multiple opposition candidates from running in the September 8 vote for Moscow city council, where 45 seats will be held up to a vote. Opposition leader Alexei Navalny had called Saturday's protest and was sentenced Wednesday to 30 days in jail for doing so.

Navalny was unexpectedly hospitalized Sunday with a severe allergy attack, his spokeswoman said.

Get Breaking News Delivered to Your Inbox

According to OVD-Info, a Russian group which has monitored police arrests since 2011, the number of the detentions from Saturday's protest reached 1,373 by early Sunday, the largest number of detainees in Russia this decade. The overwhelming majority of people were soon released, but 150 remained in custody, OVD-Info and a lawyers' legal aid group said Sunday.

Law enforcement officers detain a participant of a rally calling for opposition candidates to be registered for elections to Moscow City Duma, the capital's regional parliament, in Moscow, Russia, on Sat., July 27, 2019. Reuters

Russian police violently dispersed thousands of people who thronged the streets of Moscow on Saturday to protest the move by election authorities. Several protesters reported broken limbs and head injuries. Police justified their response by saying that the rally was not sanctioned by authorities.

Moscow police said 3,500 attended Saturday's rally but aerial footage from several locations suggested at least 8,000 people turned out.

Along with the arrests of the mostly young demonstrators, several opposition activists who wanted to run for the Moscow City Duma were arrested throughout the city.

Dmitry Gudkov, an opposition figure who was barred from running for city council office in Moscow, was detained Sunday afternoon as he delivered food to some of the Moscow protesters still in jail.

The U.S. Embassy in Moscow on Sunday decried the violent crackdown as "use of disproportionate police force" and the Russian presidential human rights council said it was concerned about the police brutality.

Russian President Vladimir Putin stayed away from Moscow over the weekend. On Sunday, he led Russia's first major naval parade in years, going aboard one of the vessels in the Navy Day parade in St. Petersburg, on the Gulf of Finland. The parade included 43 ships and submarines and 4,000 troops.