The European Union added 15 names to its list of those sanctioned in response to worsening violence in Ukraine, where separatists clubbed their way into control of another regional government headquarters Tuesday.

The EU blacklist, enacted more than a month ago, was meant to deter Russian support of the militants, but has had no visible influence on the escalating disorder in a dozen eastern Ukrainian towns and cities where the pro-Russia gunmen have taken over government facilities.

Tuesday's expansion adds penalties against government officials in the inner circle of Russian President Vladimir Putin.

A top official of the Organization for Security and Cooperation in Europe also appealed Tuesday for restoration of the "rule of law" and the release of journalists and a group of six foreign observers and an interpreter from the security alliance, which counts Russia and Ukraine among its 57 members. The team and at least two Ukrainian journalists have been held in the eastern Ukrainian city of Slovyansk since last week.

Two British television journalists also were attacked Monday by separatist protesters at a rally in Donetsk, another eastern city, said Dunja Mijatovic, OSCE media freedom chief.

"Impunity for assailants of journalists and broadcasters is escalating the tensions and contributing to the deterioration of the security situation," Mijatovic said in a statement from OSCE headquarters in Vienna. "I am dismayed by the lack of response by the law enforcement authorities to these attacks. Rule of law must be reintroduced in Ukraine."

On Tuesday, about 150 militants armed with clubs and baseball bats drove out local police from the Luhansk regional administration building. A day earlier, Mayor Gennady Kernes of Kharkiv, Ukraine's second-largest city, was shot in the back while exercising on the city outskirts. He remained in serious condition Tuesday after undergoing surgery in Israel.

In Kiev, the Ukrainian capital, Deputy Foreign Minister Danylo Lubkivsky repeated the government's accusation that the unrest was being directed by the Kremlin.

"They have no political goals, and they have no intention of holding any dialogue. They simply execute orders from Russian authorities," Lubkivsky said of the gunmen, many in Russian military garb and carrying weapons used by the Russian army.

The EU foreign ministers who agreed to new sanctions released the names of the new targets Tuesday. They include Deputy Prime Minister Dmitry Kozak; parliamentary leaders Ludmila Shvetsova and Sergei Neverov; Valery Gerasimov, the military chief of staff; and Igor Sergun, head of Russia's main armed forces intelligence directorate. All played key roles in the seizure and annexation last month of Ukraine's Crimea territory.

Unlike the United States, which has gone after oligarchs and economic targets, Europe has confined its sanctions to political and military figures. The EU relies heavily on Russian energy and trade, and is divided over stronger action against Moscow that might hurt Europe's own economic prospects.

Still, EU leaders have been alarmed by the escalating breakdown of law and order in eastern Ukraine and by what they see as Russia's abetting of the destabilizing forces.

"The downward spiral of violence and intimidation undermines the normal functioning of the legitimate state institutions" in eastern Ukraine, said Catherine Ashton, the EU's top diplomat. "A number of people have been killed, wounded, tortured or kidnapped in the last few days."

Many analysts say that the Kremlin probably is not contemplating a military incursion in or annexation of eastern Ukraine, as happened with Crimea in the south. Still, Russia has an interest in stoking tension there to keep the government in Kiev off balance and to undermine a May 25 presidential election to permanently replace Kremlin ally Viktor Yanukovich, who was driven from office in February.

henry.chu@latimes.com

carol.williams@latimes.com

Chu reported from London and Williams from Los Angeles.