Kiev and pro-Russian insurgents have agreed to withdraw their entire arsenal of smaller weapons from the buffer zone dividing rebel-held lands from the rest of Ukraine.
In airstrikes this week, the Russian military has bombed areas outside Islamic State strongholds, including one primarily held by Western-backed rebels, US officials say.
She also said she was taken prisoner by separatist, pro-Kremlin rebels hours before the journalists were killed.
The Organization for Security and Co-operation in Europe, which is monitoring a ceasefire in eastern Ukraine, reported that its monitors had seen a mobile TOS-1 “Buratino” weapons system for the first time.
The rockets have two types of warhead – either incendiary, which can spread flames over tens of kilometres, or thermobaric, which sucks up oxygen to boost the explosion.
Russian President Vladimir Putin plans to meet leaders of Ukraine, France and Germany in a revived European push to bring peace to eastern Ukraine.
A spokesman for the OSCE Special Monitoring Mission (SMM) to Ukraine told the BBC the discovery was particularly significant because of the damage the rockets could cause.
Speaking at a press conference in Luhansk on Friday, Hug expressed concern over the general humanitarian situation in villages, as well as the readiness of the heating system and access to fuel ahead of winter.
According to IHS Jane’s and the Stockholm Institute’s unofficial arms transfers database, Russian Federation has only exported the system to Azerbaijan, Iraq and Kazakhstan.
The Russian president said he hoped that the Minsk agreements previously reached between the Ukrainian warring sides in the Belarusian capital – one in September 2014 and another in February this year – would be enforced and thus end the conflict in eastern Ukraine, which has lasted for 17 months.
The Normandy Four meeting assessed all elements of the Minsk deal, including the withdrawal of heavy weapons, President Hollande said after the talks. The withdrawal is expected to take 39 days.
U.S.-Russian relations deteriorated after Russia annexed the Crimean Peninsula from Ukraine in March 2014.
Moscow denies this, but admits Russian “volunteers” are fighting with the rebels.