Ukraine says has pushed Russian troops back to the border in the region around Kharkiv, a sign it may be having increasing success in the northeast.

“The 227th Battalion of the 127th Brigade of the Territorial Defense Forces of the Kharkiv Armed Forces drove out the Russians and went to the state border,” the Ukrainian Defense Ministry statement said in a statement posted on Facebook on May 16.

Ukraine’s claim could not be immediately verified, but it comes four days after British intelligence said local forces had launched a counterattack against “vulnerable” Russian troops in an attempt to push them back across the border. Kharkiv is Ukraine’s second-largest city.

“The withdrawal of Russian forces from the Kharkiv Oblast (Region) is a tacit recognition of Russia’s inability to capture key Ukrainian cities where they expected limited resistance from the population,” the British Ministry of Defense said in a daily briefing on May 12.

While Russia has moved some troops from the north of Ukraine to the east, where battles continue to rage, Western intelligence has said Moscow’s intensified offensive in that region has also stalled.