The Ukraine government and separatist rebels fighting in the eastern part of the country exchanged hundreds of prisoners on Wednesday, in one of the largest prisoner swaps since the armed conflict began in 2014, BBC reported.

Ukraine agreed to swap 306 pro-Russian separatists in exchange for 74 of its soldiers, Al Jazeera reported. On Wednesday, Ukraine handed over 235 people, and said the others had chosen to stay in Ukraine or were released earlier.

“Some of them have already been released and the charges against them have been cleared by the Ukrainian authorities and then they prefer to stay in the government-controlled side,” Miladin Bogetic, a spokesperson for the International Committee of the Red Cross in Ukraine told BBC.

“All 74 Ukrainian hostages are already at home, on the territory controlled by our army,” Ukrainian President Petro Poroshenko wrote on Twitter.

The swap took place after months of negotiations that saw the involvement of presidents Vladimir Putin of Russia and Ukraine’s Poroshenko, and the head of the Russian Orthodox Church, the BBC report said.

The conflict

In 2014, pro-Russian separatists took over parts of eastern Ukraine’s Donbass region, sparking the conflict. A few months earlier, Russia had annexed the Crimean peninsula from Ukraine.

So far, 10,000 people, including at least 2,000 civilians, have been killed since the fighting began, Al Jazeera reported. Another 1.7 million people have had to flee their homes.