Russian troops have reportedly bombed a Red Cross aid mission in the besieged city of Mariupol.
It is believed the two bombs hit the International and the Ukrainian Committees of the Red Cross, although this has not been confirmed.
The attack hit several residential homes and a shopping centre. The number of casualties is unknown.
The news comes as Russia and Ukraine have agreed to a day-long ceasefire along a number of evacuation corridors.
Deputy Prime Minister Iryna Vereshchuk said Moscow has vowed to respect the ceasefire from 9am to 9pm in regions including Kyiv, Zaporizhzhia, and parts of the northeast.
However, Ukraine has warned that Russia is not genuine and even accused them of bombing one corridor.
The Ukrainian defence ministry said on Facebook: "Such actions are nothing other than a genocide."
The regional governor of Sumy, Dmytro Zhyvytskyy, in Ukraine, said approximately 5,000 people were evacuated from the northeastern city on Tuesday.
He added that around 1,000 cars were also able to leave as they embarked on a journey towards the city of Poltava.
Mr Zhyvytskyy said the corridor would continue to function today.
Evacuation of the region has become increasingly more difficult as Mr Zhyvytskyy said Sumy's residential area had been bombed overnight.
One of the bombs dropped on the city is reported to have killed 22 civilians. Mr Zhyvytskyy called the incident "mass murder".
Ukraine has accused Russian forces of shelling another evacuation route from Mariupol in the south of the country.
The head of Russia's National Defence Control Centre, Mikhail Mizintsev, said Russian forces would "observe a regime of silence" from 10am Moscow time to ensure safe passage for civilians wishing to leave Kyiv, Chernihiv, Sumy, Kharkiv and Mariupol, according to the Tass news agency.
However, it is unclear if the proposed routes would pass through Russia or Belarus.
Ukraine dismissed Russia's promise to allow its citizens to travel safely on designated routes to Russia or its close ally Belarus on Monday as tensions heightened further.
A Ukrainian official called it propaganda and said humanitarian concerns did not drive it.
