Anatoly Adamchuk, a reporter for the Zhukovskie Vesti, a suburban newspaper, was beaten up early on Monday, leaving him with head wounds, one of his colleagues said.
"He was attacked by two unknown individuals and hit on the back of his head and then hit again when he was on the ground," Sergei Grammatin told Moscow Echo radio.
"He has head wounds and light concussion. Now he is at home and recovering."
'Challenge to everyone'
The attack comes after a savage assault on Oleg Kashin, a leading reporter for the Kommersant newspaper, near his Moscow apartment on Saturday.
In the assault, he suffered a head injury, a shattered jaw and a broken leg and, as a result, doctors had to put him into a drug-induced coma.
No motivation for either attack has been determined, but both men wrote about efforts to stop developers from cutting down trees in forests around Moscow to build highways.
In addition, an opposition activist also trying to protect one of the areas - the Khimki forestnear Moscow - had his skull fractured in an assault last week.
The RIA Novosti news agency said that Adamchuk had been looking at plans to build a highway through the Tsagovsky forest, and had reported on the arrest by the security forces of a group of schoolchildren who had hung banners on the trees.
|The 2006 killing of Kremlin critic Anna Politkovskaya remains unresolved [AFP]
Road construction is considered one of the most corrupt sectors in Russia, offering huge profits to the businesses and officials involved who may see the journalists and activists as a direct threat to their bank accounts.
Neave Barker, Al Jazeera's correspondent in Moscow, said it is believed that any journalists that stand in the way of broader road construction plans could end up in trouble.
"That's the belief amongst the journalistic community here in Moscow and that's the belief as to why Oleg Kashin and now Anatoly Adamchuk were attacked."
Dmitry Babich, who works for Russia Profile.org, told Al Jazeera from Moscow that the reaction from media circles to Adamchuk's attack was "unprecedented".
"There were several meetings of all editors-in-chief of the Russian major newspapers. They wrote a collective letter to the president [of Russia]," he said.
"In all the newspapers, on television, every hour, there's news about Kashin; there's news about the investigation [into the attacks]. This time the outcry is really big."
But Babich said that despite the feeling among Russian journalists that the government is in some way involved in the attacks, "all the serious journalists do not blame government officials for ordering the attacks".
"They blame the government for creating in society an atmosphere when such attacks become possible," he said.
Kashin's family have urged authorities to find his attackers quickly to prove they are serious about protecting free speech.
"It's a potent challenge to the authorities. They must find them ... those scumbags," Vladimir Kashin told the Reuters news agency outside the hospital where his relative was admitted.
"By doing this a 10-minute walk from the Kremlin, they are not just throwing down a challenge to the media. They are throwing down a challenge to everyone."
There have been 19 unsolved murders of journalists in Russia since 2000, including the 2006 killing of Kremlin critic Anna Politkovskaya, according to the New York-based Committee to Protect Journalists (CPJ).
The CPJ lists Russia as the eighth most dangerous country for journalists in the world.
Dmitry Medvedev, the Russian president, has vowed to track down and punish those responsible for Kashin's attack.
Source: Al Jazeera and agencies