The Trilateral Contact Group (TCG), which is attempting to regulate the conflict in eastern Ukraine, has urged both sides to adhere scrupulously to the agreed cease-fire and to withdraw heavy weaponry away from the contact line as previously agreed.
The TCG -- which includes Ukraine, Russia, and the Organization for Security and Cooperation in Europe (OSCE) -- met in Minsk on February 1 amid a significant uptick in fighting between the Ukrainian military and Russia-backed separatists in recent days around the government-controlled town of Avdiyivka.
The TCG statement also called for "safe and secure access" for OSCE monitors and the "facilitation of humanitarian efforts" aimed at restoring water and electricity supplies.
Also on February 1, NATO Secretary-General Jens Stoltenberg called the renewed fighting "the most serious spike in violence in a long time," adding that the humanitarian situation for civilians in Avdiyivka was "dire, with 20,000 people facing freezing temperatures without heat, electricity, and water."
Stoltenberg also called on Russia "to use its considerable influence over the separatists to bring the violence to an end."
The Ukrainian military said on February 1 that nine servicemen and one civilian were also injured in the previous 24 hours.
Ukrainian officials had reported the deaths of seven soldiers in the past few days, the highest casualty toll in weeks.
An emergency official, Vladislav Husinskyy, said that 175 people, including 88 children, had been evacuated to nearby towns by bus on the morning of February 1.
Shelling left many residents of the town north of the separatist stronghold of Donetsk without electricity, water supplies, and heating in temperatures well below freezing.
WATCH: 'Humanitarian Emergency' After Fighting Escalates In Eastern Ukraine
The AP news agency quoted residents of Donetsk as reporting incessant outgoing and incoming artillery salvos through the night and in the morning.
Separatists said two civilians were killed and another wounded in the shelling of Donetsk and the neighboring town of Makiyivka.
The UN Security Council on January 31 expressed "grave concern" over the "dangerous deterioration" in eastern Ukraine and called for a halt to the violence.
Kyiv and Moscow are accusing each other of being responsible for the recent escalation, with Ukraine's Foreign Ministry describing it on January 31 as "a clear indication of Russia's continued blatant disregard of its commitments under the Minsk agreements."
Speaking on February 1, Kremlin spokesman Dmitry Peskov rejected accusations that Russia and the separatists were responsible for the flare-up of hostilities, and called on Kyiv to stop what he said were "provocative actions."
Peskov also said that the escalation was evidence what he called the need for "a swift resumption of dialogue and cooperation between Russia and the United States."
Russian-U.S. relations are badly strained over Moscow's aggression in Ukraine, its actions in Syria, and what U.S. intelligence agencies say was state-directed interference in the U.S. presidential election.
U.S. President Donald Trump has called for improved relations with Russia, and both the White House and Kremlin said a conversation between Trump and Russian President Vladimir Putin on January 28 was a positive sign.
Despite substantial evidence, Russia denies claims by Kyiv, NATO, and Western governments that it stirred up separatism in the region and has sent troops and weapons to Ukraine to support the separatists.
The European Union, United States, and other states have imposed sanctions on Russia over the conflict, as well as for its annexation of Ukraine's Crimean Peninsula in March 2014.
With reporting by Christopher Miller, AP, UNIAN, TASS, and Interfax