Ukraine and the West have accused Russia of launching a new incursion into Ukraine's eastern region after a meeting between Russian and Ukrainian leaders Tuesday made no breakthrough in the months-long crisis.
Ukrainian military spokesman Andriy Lysenko said Wednesday that a group of Russian soldiers had crossed the border in armoured infantry carriers and a truck and entered the town of Amvrosiyivka, not far from where Ukraine detained 10 Russian soldiers on Monday.
Ukraine's State Security Service also said in a statement that it had detained another Russian soldier in the east of the country who has confessed his unit provided military support to separatist rebels.
"These incursions indicate a Russian-directed counter-offensive is likely under way in Donetsk and Lugansk," US State Department spokeswoman Jen Psaki told reporters Wednesday.
Psaki also said that Washington has noted "the Russian government's unwillingness to tell the truth even as its soldiers are found 30 miles (48 km) inside Ukraine."
White House spokesman Josh Earnest said the military movement "would be consistent with the other kinds of destabilizing military activities that Russia has pursued in Ukraine."
In a telephone call with Russian President Vladimir Putin, German Chancellor Angela Merkel demanded explanation of a new Russian military incursion into Ukrainian territory, Merkel's spokesman Steffen Seibert said.
"She emphasized Russia's major responsibility for de-escalation and watching over its own frontiers," Seibert said.
A senior NATO diplomat told reporters on condition of anonymity that Russian support for the separatists was becoming increasingly obvious.
The diplomat said sophisticated weapon systems were found in the area, including the SA-22 surface-to-air missile, which is more advanced than the SA-11 system that was said to have shot down a Malaysia Airlines jet.
Russia denies sending weapons and soldiers to help the rebels and says the men captured Monday had crossed an unmarked section of the border by accident.
On Monday, the Ukrainian State Security Service claimed to have seized servicemen from Russia's regular army and published a video footage on its Facebook page, showing people dressed in military camouflage.
Russia's RIA Novosti news agency cited a source in the Russian Defense Ministry as saying that those captured servicemen were involved in patrolling the Russian-Ukrainian border area and "most likely crossed border by accident."
Besides, Moscow denies reports that it held secret negotiations with the United States over the Ukraine crisis in Finland in June.
"We admit the Russian and US experts have actually met in late June at the Finnish island of Boisto. Those were not the state official consultations but just a contact between Russian and US non-government structures and academic communities," the Foreign Ministry said in a statement Wednesday.
The ministry said the solution to the Ukraine crisis had been discussed during the meeting, but it was "completely open to the public," according to an Itar-Tass report.
Violence in eastern Ukraine escalated in April, one month after Ukraine's Crimea declared independence and eastern Donetsk and Lugansk regions wanted to follow Crimea's steps.
The conflict between government troops and pro-independence militia has killed more than 2,000 people in eastern and south-eastern Ukraine, with hundreds of thousands of others displaced.
The crisis also turned into a trade war, in which the United States and the European Union (EU) imposed sanctions on Russia's finance, oil and defence sectors and Moscow hit back by banning most Western food imports.
On Tuesday, leaders of the three Customs Union states -- Belarus, Kazakhstan and Russia -- and Ukraine as well as EU representatives met in the Belarusian capital of Minsk to discuss the Ukraine crisis and economic cooperation.
Putin and Ukrainian President Petro Poroshenko also held a landmark bilateral meeting on the sidelines of the summit.
However, no breakthrough was made though all sides at the summit have agreed on a peace plan prepared in June by Poroshenko.
Participants also agreed that the Contact Group for Ukraine, comprising representatives of Russia, Ukraine, the rebels and the Organization for Security and Cooperation in Europe, resume work in the coming days, Kremlin spokesman Dmitry Peskov said Wednesday without specifying the exact time of the resumption.
"Agreement has been reached that the Contact Group must resume its work as quickly as possible," Putin said earlier after the Minsk summit, assuring that Russia would do everything for that.
But Ukrainian Foreign Policy Adviser Valery Chaly told reporters in Kiev that Poroshenko's declaration on a cease-fire roadmap did not mean an immediate end to the government's military offensive against the rebels.
"If there are attacks from the terrorists and mercenaries, then our army has the duty to defend the people," he said. KIEV, August 28 (Xinhua)