Ukrainian soldiers withdrew their 82 mm calibre mortars from the villages of Pisky and Opytne near the ruins of Donetsk airport, which was ravaged by intense fighting last year, army spokesman Oleksandr Zavtonov told AFP.
Kiev's withdrawal came after pro-Moscow rebels said they pulled out their light arms from the area on Thursday.
A military convoy transporting mortars could be seen moving away from government positions in Pisky towards an arms depot, an AFP journalist said.
"We do not respond to the rebels' provocations or shots. But if we must defend ourselves, we now only have guns, Kalashnikov (rifles) and stones," said 39-year-old Eduard, a soldier in Ukraine's 93rd Brigade.
Today's pullout completed the government's weapons withdrawal from the Donetsk area and was in line with a trust-building September 1 pact that ordered the withdrawal of all weapons with a calibre under 100 mm.
While the deal led to a marked de-escalation in one of Europe's deadliest crises since the Balkans wars of the 1990s, it remains unclear whether this semblance of calm will last.
A peace deal signed in February in Minsk calls for a vote to be held in the separatist regions under international auspices. Those elections have now been pushed back to early 2016.
Both the government and the rebels say they have honoured a pullout deal regarding larger weapons.
But the Organization for Security and Cooperation in Europe (OSCE), tasked with overseeing the withdrawal, has said some heavy weapons remain deployed on both sides of the frontline.