KIEV, Aug. 15 – Three television channels went on strike on Saturday in protest of steadily increasing pressure on media in Ukraine, with hundreds of other journalists declaring readiness to join the action.

Channel 5, TVi and Chernomorska went on the strike by cutting for one hour their live broadcasts ahead of a court ruling over television frequencies on Monday.

Channel 5 and TVi may lose their frequencies after a rival television group, owned and controlled by Ukraine’s security service chief Valeriy Khoroshkovskiy, sued the channels in June.

Should the channels lose the frequencies, their expansion into Ukrainian regions would be reversed, effectively reducing their broadcast to few cities, such as Kiev.

That may undermine the channels financially by reducing their potential advertizing revenues, and may eventually trigger massive layoffs of journalists.

“We see that attempts have been made over the past months to destroy the freedom of speech and to monopolize the information space by representatives of the Ukrainian authorities,” the channels said in a statement. “The strike is a cardinal step.”

The developments come as the number of attacks on journalists has been rising in Ukraine triggering significant concerns among domestic and international media watchdogs.

As the latest example of the trend, Yuriy Mykhaylovych, an independent television journalist in Dnipropetrovsk, was assaulted by unknown attackers on Sunday.

Mykhaylovych, who was injured and left lying on the ground for 40 minutes before an ambulance had arrived to assist him, said the attack may be a revenge for his reports critical of the local authorities.

“I am convinced that this is an open pressure on the free media from the local authorities, from the most senior local officials,” Mykhaylovych said at a press conference.

This attack comes as another reporter, Vasyl Klementyev, the chief editor of the local Kharkiv newspaper Noviy Stil, has gone missing since August 11.

The newspaper has been running reports critical of law enforcement agencies.

The number of attacks has been growing rapidly since Viktor Yanukovych, a pro-Russian figure, has won the presidency in February.

There were no attacks journalists reported during the five years of presidency of Viktor Yushchenko, a pro-Western figure, underscoring a shocking reversal of policy over the past six months.

“The authorities are trying to turn the country’s life – politics, economy and mass media – into black-and-white mode,” Anatoliy Hrytsenko, an opposition leader, said in his blog on Sunday. “This is extremely dangerous for the stability of the society and the state.”

“It’s dangerous for the freedom and for democracy in Ukraine,” Hrytsenko said.

Meanwhile, more Ukrainian journalists may be joining the protest against the pressure on media after censorship watchdog, Stop Censorship, declared its readiness to participate.

The International Press Institute (IPI), the world’s oldest global press freedom organization, in an open letter to Yanukovych on Wednesday, expressed concerns over “significant deterioration” in the press freedom in Ukraine.

The Vienna-based IPI is the second major international media organization to issue the criticism in less than a month after the Paris-based Reporter Without Border had slammed the authorities with the same criticism on July 20. (tl/ez)