CRI听力:Ukraine Crisis: 30 People Killed in Attack on Mariupol

Ukrainian President Petro Poroshenko has chaired an emergency roundtable meeting of the country's National Security and Defence Council.

The meeting comes after at least 30 people were killed in the southeastern Ukrainian city of Mariupol on Saturday when rockets slammed into a market, schools, homes and shops.

Poroshenko condemne the violence, blaming what he called "terrorists" supported by Russia for the attack, citing intercepted radio and telephone conversations.

"On Monday, there should be a meeting of foreign ministers of the EU where we'll coordinate further steps to provide the security of Ukraine and to increase pressure on Russia."

Poroshenko cut short a trip to Saudi Arabia in order to coordinate the government's response.

Mariupol is a strategically situated port city under Ukrainian control and had been relatively quiet for months.

On a visit to India, US President Barack Obama also expressed his concern over the situation in Ukraine.

"We will continue to take the approach we have taken in the past which is to ratchet up the pressure on Russia, and I will look at all additional options that are available to us short of military confrontation and try to address this issue."

Russia insists it does not support the rebels.

Russian Foreign Minister Sergei Lavrov has spoken separately with European Union foreign affairs chief Federica Mogherini and U.S. Secretary of State John Kerry, saying the Ukrainian government bore responsibility for the latest military escalation.

However, Lavrov did not directly address who had carried out the attack on Mariupol and said that it should be investigated.

Mogherini has announced that EU foreign ministers would hold an "extraordinary" meeting in Brussels on Thursday to discuss Ukraine.