Moscow's City Hall announced Monday that it would close Triumfalnaya Ploshchad for large-scale construction work, hours after it told opposition activists that they could not rally there because a pro-Kremlin group had reserved the space first.

The closure, ordered for the construction of an underground parking garage for 1,000 cars, appears to offer the authorities a months-long solution to their problem of dealing with the opposition's regular attempts to stage rallies on the square on the 31st day of every month.

It also promises to create a new traffic headache in central Moscow as construction spills out onto 1st Tverskaya-Yamskaya Ulitsa and the Garden Ring, the two main roads that intersect on the square near the Mayakovskaya metro station.

A City Hall spokesman said the square would be closed off “in the coming days,” Interfax reported. He did not elaborate on how long the work would take or how it might impede traffic. Similar work just up the street on Ploshchad Tverskaya Zastava, near the Belorusskaya metro station, has caused huge traffic jams in the area.

The announcement came as something of a surprise after city authorities earlier Monday rejected an opposition request to stage an Aug. 31 rally, saying Young Russia, a pro-Kremlin youth group, had already asked permission to stage a blood drive there.

Police, incidentally, also detained one of the opposition activists who came to file the request, Dmitry Putenikhin, on suspicion of making an unauthorized video in the City Hall building, Interfax said, without elaborating whether he faced any charges over the incident.

Eduard Limonov, head of The Other Russia opposition coalition, said activists would rally despite the construction work.

“We will come to Triumfalnaya. What do we care about construction?” he said, Interfax reported.

He added that City Hall was "looking for a global solution" to the opposition rallies.

But human rights champion Lyudmila Alexeyeva, another co-organizer of the rallies, said she and other activists would have to discuss whether to stage the event.

“They are going to reconstruct it? I thought they were about to build a children's hospital there,” she said, jokingly.

“We haven't decided anything,” she added.

Activists have filed requests to rally on Triumfalnaya Ploshchad to call attention to Article 31 of the Constitution, which guarantees the right of free assembly, since last year, but none has been granted, and the events regularly end in police crackdowns.

Meanwhile, the first person will be sent to prison in connection with the rallies after the Moscow City Court on Monday upheld a lower court's decision to sentence Tver region resident Sergei Mokhnatkin to 2 1/2 years in prison for beating a police officer at a Dec. 31 rally, Interfax reported.

Mokhnatkin, 56, did not participate in the rally but reprimanded a police officer who was tussling with an elderly woman and headbutted the officer after being detained, breaking his nose. The officer faced no penalties over the incident. Mokhnatkin's lawyer promised to appeal.