MOSCOW (AP) — Russian law enforcement agents on Thursday searched the apartments and offices of several opposition activists who campaigned against constitutional amendments that allowed President Vladimir Putin to extend his rule until 2036.

Investigators searched the apartment of municipal lawmaker Yulia Galyamina and also raided offices and homes of several activists who took part in the “No!” campaign over the July 1 constitutional vote, in which nearly 78% of voters approved the changes that allow Putin to seek two more presidential terms.

The raids come ahead of a protest against the constitutional amendments that the activists planned for next Wednesday in Moscow and St. Petersburg. Authorities have denied permission, citing a ban on public gatherings during the coronavirus pandemic.

Investigators also searched the offices of MBK Media news outlet and Open Russia group that are funded by self-exiled tycoon and Kremlin foe Mikhail Khodorkovsky, and detained several activists.

Officials said the searches were linked to a new investigation into Khodorkovsky's Yukos company, but activists at both MBK and Open Russia saw them as an official response to their campaign against the constitutional vote.

Khodorkovsky moved to London after spending 10 years in prison in Russia on charges widely seen as political revenge for challenging Putin’s rule.