Ban called for maximum restraint and appealed to all sides to work towards calming the situation, which has the "growing potential" to spark violent clashes.
"The Secretary-General stresses that further disturbances will not serve the interests of any side. He therefore appeals to all sides to work towards calming the situation, adhere to the rule of law and exercise maximum restraint," a statement issued by his spokesperson said yesterday.
Ban expressed deep concern about possible fresh clashes in strife-riven Ukriane after anti-government protesters in the small eastern city of Slavyansk took over the main police building and constructed barricades along roads leading into the town, which is located some 90 miles from the Russian border.
Calling for urgent and constructive dialogue to deescalate the situation and address all differences, Ban also stressed that the UN stands ready to continue to support a peaceful resolution to the current crisis facing Ukraine.
Months of political unrest in Ukraine led to the removal by Parliament of President Viktor Yanukovych in February, followed by increased tensions in the country's autonomous Crimea region, where a secession referendum was held in March, in which the majority of the people voted to join Russia.
Ban and other senior UN officials have been pushing for a diplomatic resolution to the crisis.
After returning from a visit to both Ukraine and Russia in late March, he called for a solution based on the principles of the UN Charter and warned the concerned parties -- and the wider international community -- that "at this time of heightened tensions, even small sparks can ignite larger flames of unintended consequences."
The 15-nation UN Security Council held an emergency meeting late yesterday to take stock of the situation.
US Ambassador to the UN Samantha Power said the armed seizure of buildings in six eastern Ukrainian towns "mirrors the tactics" Russian forces used in the early stages of the Crimea invasion.
"The human stakes of what is happening in Ukraine are extremely high. The lives of innocent civilians are at risk, yet we are being bombarded by Russian disinformation and propaganda while the Ukrainians are being confronted by incitement and violence. Russian media and government spokespersons are spreading fiction, so we must focus on facts," she said.
Aiming to deescalate the situation in Ukraine, US Secretary of State John Kerry would participate in the Geneva talks on April 17, which will include Russian Foreign Minister Sergey Lavrov.
Power said if the talks have to be successful, Russia would have to explain why its forces, almost 40,000 in number, continue to mass on the Ukrainian border and it would have to come with constructive ideas on how to deescalate and resolve the armed attacks on buildings in eastern Ukraine.