KYIV, Ukraine -- Hundreds of journalists and opposition activists gathered outside the Interior Ministry headquarters in Kyev on Wednesday, demanding the resignation of Interior Minister Vitali Zakharchenko after the attack on Tetyana Chernovil.

Some held pictures of Chernovil, who has also been one of the leaders of mass demonstrations that have rocked the Ukrainian capital for more than a month since Yanukovych decided to scrap a deal with the EU in favor of forging stronger ties with Russia.

Chernovil has written for Ukrainska Pravda, as well as other pro-opposition news outlets.

"Shame! Shame!" yelled the demonstrators, some of whom held pictures of Chernovil's battered, bruised and swollen face.

Chernovil, 34, was attacked as she was driving home. Her car was cornered by a sports utility vehicle. When she tried to flee, she was beaten by several men. Chernovil sustained a concussion, as well as fractures to her nose and face, said her husband Mykola Berezovy.

The attack took place hours after Chernovil published an article on a posh suburban residence which she claimed was being built for Zakharchenko.

The protesters have been demanding Zakharchenko's resignation after a violent crackdown on a small rally last month left dozens injured. They have also accused Zakharchenko and other members of Yanukovych's inner circle of profiting while other Ukrainians suffer.

Yanukovych is accused of illegally appropriating a giant estate outside Kyiv and building a palatial complex in what critics have called an example of corruption. He denies owning the estate and says he only occupies a small house on its territory.

Chernovil unsuccessfully ran for Parliament on the opposition ticket last year.

In the run-up to the election last summer, she also broke into Yanukovych's heavily guarded palatial residence in an attempt to expose corruption there.

Yanukovych condemned the attack on Wednesday and ordered a thorough investigation.

"We express our concern at a strikingly similar series of events over the last few weeks, targeting individuals, property, and political activity ...," the U.S. Embassy said in a statement.

World boxing champion and opposition leader Vitali Klitschko accused the authorities of trying to intimidate opposition activists and called for nation-wide boycott of the government.

"They want to paralyze people with fear. This is not going to happen." Klitschko said.

The attack on Chernovil has been the latest in a series against activists.

On Tuesday, Dmytro Pylypets, an organizer of opposition protests in the eastern city of Kharkiv was beaten and stabbed by unknown assailants.

Members of the watchdog group Road Control, which has accused Ukraine's traffic police of corruption, also say they've been subjected to more attacks since they started helping protesters in the sprawling protest encampments in Kyiv.

In recent weeks, two of their activists were arrested, one was beaten and another one was shot after he refused to disclose information on the group.

The group has posted videos which they say show officers extorting and accepting bribes. It also claims to have exposed a scheme during which police tow cars to private parking spots purportedly owned by people affiliated with police. After the car owners spend days trying to contest fines, they are reportedly slapped with huge parking bills.

"They want to destroy us - either jail us, or chase us away abroad or just kill us off one by one," claimed group spokesman Yehor Vorobyov.

Authorities have denied waging a campaign against the group.

"There has been no so-called hunt," Interior Ministry spokesman Serhiy Burlakov said in an interview with The Associated Press. "We only act within the framework of the law."

Burlakov said police are investigating cases of alleged bribe-taking, but he denied the existence of the parking scheme.

Oleksandra Matveichuk, head of the Center for Civic Freedoms, said the harassment of activists goes to the heart of the anti-government protests spreading through Ukraine.

"Here we are witnessing clear politically motivated persecution in various ways," Matveichuk said.

"If people who defend human rights are attacked ... it means we can no longer speak of any democracy. The line has been crossed."