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.

In Ukraine’s capital, activists protested after the city’s authorities tried to remove the tent camp that was the center of deadly protests that 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,” Klitschko said to a crowd that at times jeered and whistled. “Parliamentary elections must be held in the nearest future.”

One Ukrainian soldier and several insurgents were wounded as troops repelled a rebel attack on the Donetsk Airport yesterday. About 80 pro-Russian rebels attacked a border guard base in the Dyakove village in the Luhansk region, wounding three servicemen, the border guard service said on its website, while a government fighter jet helped repel the attack.

Rebels probably used the night assault as a diversion to smuggle guns from Russia across other sections of the border, according to the statement. Two days earlier, the separatists downed a military helicopter with a shoulder-fired missile, killing a general and 13 soldiers.

Leaders in Kiev and the U.S. and EU accuse Russian President Vladimir Putin of encouraging the tumult by sending the separatists cash, arms and manpower. Russia says Ukraine’s army should stop targeting its own citizens, a sentiment echoed by Czech President Milos Zeman, whose country is a member of the EU and the North Atlantic Treaty Organization.

“When the Ukrainian army, including paramilitary organizations, fight against their own citizens, they are still citizens of Ukraine,” Zeman said in an interview on Czech Television today. “They should also realize that if it really comes to civil war, it would be a very comfortable pretext for the Russian Federation to invade.”

In a speech in Singapore, Russian Deputy Defense Minister Anatoly Antonov criticized “punitive action” by Ukraine’s central government. Authorities in Kiev say they’re fighting rebels from Ukraine and some fighters from Russia who have terrorized the country’s east by killing dozens of soldiers and civilians and abducting scores of journalists, pro-Kiev activists and electoral officials.

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,” 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 Yanukovych’s ouster.

About 90 of the 300 people that went missing during February protests before 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 on May 26 and May 30, 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 yesterday 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 on June 2 and Ukraine doesn’t rule out arbitration as a solution.