Four European Union members that once were under the Soviet sphere are criticizing the arrest of former Ukrainian Prime Minister Yulia Tymoshenko for alleged abuse of power.

The Czech Republic, Hungary, Poland and Slovakia say all Ukrainians are entitled to fair, transparent and independent judicial proceedings.

Czech President Vaclav Klaus sent a personal letter to Ukrainian President Viktor Yanukovych, saying he hopes Ms. Tymoshenko's trial will not be used to settle any personal political scores.

The United States called Ms. Tymoshenko's arrest politically motivated and demanded her immediate release.

Ms. Tymoshenko is charged with abuse of power stemming from a 2009 deal that ended Russia's gas cutoff to Ukraine. Mr. Yanukovych's government says she broke the law by not consulting with her government before signing the deal.

The former prime minister is one of about 400 officials under investigation for crimes allegedly committed while in office. Critics say the only cases that have come to trial involve political figures opposed to President Yanukovych.

Ms. Tymoshenko rose to fame in 2004 as a leader of Ukraine's “Orange Revolution” street campaign that forced the Supreme Court to toss out the results of a disputed presidential election won by Mr. Yanukovych. The two met in last year's 2010 presidential election, which Mr. Yanukovych won.

Ms. Tymoshenko is expected to be the main opposition candidate in next year's election. She will not be eligible to run if she is convicted.