KIEV, Ukraine -- Crimea adopted the ruble in a further step toward integration with Russia, which annexed the Black Sea peninsula in a move Ukraine and its allies the U.S. and European Union have denounced as illegal.
Crimean shops will no longer use double pricing in hryvnia and rubles, and all transactions will be carried out solely in the Russian currency, Russia's central bank said in a statement. The currency switch comes as Ukrainian forces battle to stop pro-Russian separatists from carving off more territory in the country's east as President-elect Petro Poroshenko tries to right the economy and keep the country from splitting apart.
Also in the region, the president of Abkhazia, a breakaway region of Georgia heavily supported by Russia, resigned Sunday after less than a week of chaotic unrest during which demonstrators stormed the presidential administration building and the Kremlin sent high-level emissaries from Moscow in a bid to calm the situation.
On Friday, Parliament voted to oust the president, Alexander Z. Ankvab, designated its speaker, Valery Bganba, as the acting president and scheduled an early presidential election for Aug. 24. Mr. Ankvab initially rejected Parliament's actions and insisted that he would remain in office.
But on Sunday evening, Mr. Ankvab resigned from office after issuing a long, rambling statement in which he accused his opponents of violating the Abkhaz Constitution and of breaking moral standards.
Abkhazia is heavily dependent on Russian economic aid and security assistance, and those involved in the recent unrest appeared generally to support close ties with the Kremlin. The opposition to Ankvab, who was elected in August 2011, seemed largely based on his failure to end corruption and improve the country's financial situation.
In Ukraine's capital, activists protested after the city's authorities tried to remove the tent camp that was the center of deadly protests and led to the February ouster of former President Viktor Yanukovych. Kiev Mayor-elect Vitali Klitschko, an ex-world boxing champion, said general elections should be held as soon as possible.
"The things we are doing are going step-by-step," Mr. Klitschko said to a crowd that at times jeered and whistled. "Parliamentary elections must be held in the nearest future."
Ukrainian forces are continuing to fight insurgents in eastern regions, Defense Ministry spokesman Vladyslav Seleznyov said by phone.
"Each of the men taking part in the anti-terrorist operation is carrying out his task on schedule, and more information will be provided after the military action is over," Mr. Seleznyov said.
Armed men wearing Russian Cossack uniforms attacked a Ukrainian Orthodox church of the Kiev Patriarchate in Crimea near Simferopol, wounding two women, the Journalists' Investigation Center says, citing Archbishop Klyment.
The attackers shouted "satanists" and "fascists," Archbishop Klyment said, according to the Journalists' Investigation Center. They are trying to push the Ukrainian Orthodox Church out of Crimea, he said.
More than 1,000 people gathered in Kiev's Independence Square to protest removal of tent camp and commemorate 100 victims of deadly clashes three months ago that preceded Mr. Yanukovych's ouster.
About 90 of the 300 people that went missing during February protests before Mr. Yanukovych fled have not yet been found, and police haven't done their job, Maidan volunteer leader Taras Matviyiv said.
Meanwhile, the Organization for Security and Cooperation in Europe said it still had no contact with two observer teams it sent to monitor the unrest in eastern Ukraine that went missing in Luhansk region last Monday and Friday, according to Michael Bociurkiw, the OSCE's spokesman in Kiev.
The organization has information that they are safe and "has confidence" they will be released in the future.
After talks brokered by the EU in Berlin, Ukraine its first payment in months Saturday to Russia's OAO Gazprom, transferring $786 million to pay for gas received in February and March.
While debts and future payments remain in dispute, EU Energy Commissioner Guenther Oettinger welcomed the move as "building blocks for a package that, given the evident goodwill of all parties today, doesn't seem out of reach." Talks are due to continue today, and Ukraine doesn't rule out arbitration as a solution.
The New York Times contributed.