section_path: History/War in the Donbas (2014–2021)/Minsk agreement and continued fighting
section_name: Minsk agreement and continued fighting
paragraph_text: Minsk agreement and continued fighting
  
  On 3 September 2014, Poroshenko said he and Putin had reached a "permanent ceasefire" agreement. Russia denied this, denying that it was a party to the conflict, adding that "they only discussed how to settle the conflict". Poroshenko then recanted. On 5 September Russia's Permanent OSCE Representative Andrey Kelin, said that it was natural that pro-Russian separatists "are going to liberate" Mariupol. Ukrainian forces stated that Russian intelligence groups had been spotted in the area. Kelin said 'there might be volunteers over there.' On 4 September 2014, a NATO officer said that several thousand regular Russian forces were operating in Ukraine.
  
  On 5 September 2014, the Minsk Protocol ceasefire agreement drew a line of demarcation between Ukraine and separatist-controlled portions of Donetsk and Luhansk Oblasts.
  
  Despite the Minsk ceasefire, sporadic clashes continued around Donetsk International Airport, the last part of Donetsk city held by Ukrainian troops. On 28 September, Russian-backed forces began an offensive to capture the airport. Ukrainian troops were besieged in the terminal and control tower. They were given the nickname " Cyborgs ", as they withstood repeated Russian attacks in grim battlefield conditions. The siege lasted throughout winter and most of the airport was destroyed by shelling. Eventually, on 21 January 2015, rebels took the airport with help from Russian special forces.
  
  On 7 and 12 November, NATO officials reconfirmed the Russian presence, citing 32 tanks, 16 howitzer cannons and 30 trucks of troops entering the country. NATO said it had seen an increase in Russian tanks, artillery pieces and other heavy military equipment in Ukraine and renewed its call for Moscow to withdraw its forces. The Chicago Council on Global Affairs stated that Russian separatists enjoyed technical advantages over the Ukrainian army since the large inflow of advanced military systems in mid-2014: effective anti-aircraft weapons (" Buk ", MANPADS) suppressed Ukrainian air strikes, Russian drones provided intelligence, and Russian secure communications system disrupted Ukrainian communications intelligence. The Russian side employed electronic warfare systems that Ukraine lacked. Similar conclusions about the technical advantage of the Russian separatists were voiced by the Conflict Studies Research Centre.