MOSCOW — Two associates of the Russian opposition leader Aleksei A. Navalny were sentenced to jail on Wednesday after hosting a webcast about nationwide protests in Russia.

The two activists, Ruslan Shaveddinov, a spokesman for Mr. Navalny’s campaign, and Kira Yarmysh, who works for Mr. Navalny and his foundation, were detained in Moscow on Tuesday.

They were quickly found guilty of breaching rules for demonstrations by giving publicity to a “voters’ boycott” protest that was held last Sunday. As the protest was unfolding, Mr. Shaveddinov and Ms. Yarmysh were covering it through a live feed on YouTube and on their Twitter accounts.

Mr. Shaveddinov was sentenced to eight days in jail, and Ms. Yarmysh was sentenced to five days in jail.