Medvedev told reporters— after meeting Czech counterpart Vaclav Klaus — that the law may have been violated during Sunday’s vote.

Russian protesters, undeterred by the deployment of tens of thousands police officers, have taken to the streets in Moscow and St. Petersburg for three straight nights, outraged over observers’ reports of widespread ballot box stuffing and manipulation of the vote count in Sunday’s parliamentary election.

Police have detained hundreds in what have been some of the biggest and most sustained protests in years.

Medvedev tried to play down the protesters’ complaints Thursday.

“What’s happening in Russia is quite natural. Some people are disappointed, some disoriented,” he said. He called for Russians to remain calm during any inquiry, adding that “experts, not ordinary people” would investigate.

“Our electoral law is not ideal,” he admitted. “It’s time to give the new parliament a chance to work and, of course, to investigate everything that happened.”

Medvedev said he can understand some people are disappointed with the result, but “the outcome fully corresponds with estimates from analysts and public polls ... (and) fully reflects the mood in our society.”

He said people have a right to express their view and ask questions, but “it’s a key condition,” that they to do it in line with the law.

Medvedev, returning to the Czech capital over a year after he and then United States President Barack Obama signed a landmark arms control treaty, is in Prague to talk business .

During his two day visit, 14 contracts have been signed between the two sides, among them a deal to allow a Prague-based company to repair and upgrade Russian-made Mi helicopters widely used by many countries around the globe, including NATO members and by Afghanistan.

The Czech Republic will also build a railway track and two power plants in Russia, including one in Sochi for the 2014 Winter Olympics in Russia’s south — according to a contract signed Thursday.

High on the agenda Thursday was Medvedev’s support for a multibillion-dollar bid by a consortium led by Russia’s Atomstroiexport to build two more reactors at the Czech Temelin nuclear power station.

US-based Westinghouse Electric Co., a subsidiary of Japan’s Toshiba Corp., and France’s state-owned nuclear engineering giant Areva SA are also bidding for the lucrative deal, with an estimated value of more than $10 billion.

“It’s an interesting project for us,” Medvedev said. “The Czech Republic will have to choose which of the three partners is more interesting.”