A Kremlin critic running for mayor of the city hosting the 2014 Winter Olympics said he was doused with ammonia Monday in an attack he blamed on the government.

Boris Nemtsov told Ekho Moskvy radio he suspects Kremlin-backed activists carried out the attack in response to his criticism of Russia's plans for the Winter Games in the Black Sea resort city of Sochi.

A Kremlin spokesman said he could not immediately comment on the allegation.

The incident coincided with the publication of an open letter to President Dmitry Medvedev in which Nemtsov said preparations for the Olympics will strain Sochi to the breaking point and suggested many events be held elsewhere in Russia.

Nemtsov was attacked outside his campaign headquarters in Sochi, spokeswoman Olga Shorina said by telephone. She said a person with long hair, women's clothes and a deep voice approached him with a bouquet of flowers while an assailant splashed him with ammonia.

Some got in his eyes, but he apparently suffered no lasting injury and went ahead with a scheduled news conference after a delay, Shorina said. Police were called immediately, but more than an hour later they had yet to arrive, she said.

Nemtsov, a Sochi native, is a liberal politician who served in Russia's government in the 1990s — including two stints as a deputy prime minister. He was became an increasingly vocal critic of Vladimir Putin, now prime minister, during his eight-year presidency.

His mayoral bid will increase attention on the election April 26 election in Sochi. The vote comes amid Russia's worst economic crisis in at least a decade, which has raised concerns about the ambitious and costly plans for the Olympics.

According to Echo Moskvy, Nemtsov said he suspects he was attacked by members of the pro-Kremlin youth group Nashi (Ours). Representatives of the group could not immediately be reached for comment.

Nemtsov linked the attack to his letter, published Monday in the opposition newspaper Novaya Gazeta, and to a critical report he said he and others are compiling that would "reveal the truth" about the Olympic preparations.

"Naturally, this is not very pleasant for the government, and they are fighting against us with their criminal methods," Ekho Moskvy quoted him as saying.

The International Olympic Committee awarded the 2014 Games to Sochi after an impassioned address by Putin, who personally backed the bid. Holding the games will require major upgrades to roads and other infrastructure, and the venues for ice sports must be built from scratch.

In his letter to Medvedev, Nemtsov said that Sochi cannot handle the games without major improvements that would cost even more than current plans and that construction for the Games will cause irreversible environmental damage and drive people from their homes.