KIEV, May 24 – Ukrainian authorities briefly detained opposition leader Yulia Tymoshenko on Tuesday, sparking a wave of international concerns and diplomatic activity, while also raising questions the move may have been politically motivated.

She was released from custody later that day, signaling the authorities may have tried to test international and domestic reactions to the possibility that the leading opposition figure may be arrested.

The test raised an outrage among Tymoshenko’s followers and political allies in Europe, including the European People’s Party, which expressed major concerns with the development.

“I strongly condemn the arrest of Yulia Tymoshenko,” Wilfried Martens, the president of the European People’s Party and a former prime minister of Belgium, said in a posting on Twitter on Tuesday. “I will be following the situation very closely.”

Jerzy Buzek, the president of the European Parliament, also expressed concerns, adding the move raises questions about “politically motivated” case against the opposition leader.

The reaction puts mounting pressure on President Viktor Yanukovych as Ukraine has been already alleged of drifting towards authoritarian rule over the past 12 months. International human rights and media watchdogs complained about deteriorating freedom of speech and the overall level democracy in the country.

Seeking to calm down the international concerns, Prosecutor General Viktor Pshonka on Tuesday met with foreign diplomats, including U.S. Ambassador John Tefft, and ambassadors representing countries of the European Union, and the European Commission in Ukraine.

Pshonka briefed the diplomats on the latest developments and the case against Tymoshenko, accusing her of intentionally delaying the investigation.

Tymoshenko, emerging from the Prosecutor General’s Office to the cheers of her supporters later on Tuesday, accused Yanukovych of trying to jail his political opponents for extending his political rule.

“Unlike you, Mr. Yanukovych, I don’t have either law enforcement troops or a repressive apparatus, or a gang that has been surrounding you, or billions of [dollars] you have stolen from this country,” Tymoshenko said.

“Perhaps, I don’t have anything, but after your actions like these, believe me, you look much weaker then I even with all those guns,” Tymoshenko said. “That’s because you are scared, not me.”

Tymoshenko is accused of negotiating the gas agreement in January 2009 that had set a very high natural gas price for Ukraine that now had threatened its economic recovery, according to Prime Minister Mykola Azarov.

Tymoshenko tried to stop the investigation, but a Kiev district court last week had rejected her lawsuit, allowing the investigation to proceed.

The detention of Tymoshenko also triggered criticism within Ukraine with Arseniy Yatseniuk, the second most popular opposition leader, warned the move would lead to further political escalation and boycott by opposition lawmakers.

“If the authorities go ahead with this, they will never explain to the people and to the world that this is an honest investigation into a criminal case, not a political vendetta,” Yatseniuk said.

“If Tymoshenko is arrested, not a single opposition lawmaker must appear in Parliament,” Yatseniuk said. “We will go to the people. After this decision, this would not be a Parliament. This will not be the government, but the junta.” (tl/ez)