Crimea protests
Pro-Ukraine protesters attend a rally denouncing an upcoming referendum on the future of the Crimean peninsular in Simferopol, on March 14, 2014. Reuters/Thomas Peter

Two people were killed and six injured in the second day of clashes between pro-Russian and pro-Ukrainian activists in Kharkov in north-eastern Ukraine on Friday, news reports said.

Amid Moscow’s tightening grip over Crimea, clashes started between rival activists leading to the arrest of 30 people, who had laid down weapons and surrendered to police after fighting throughout the night. The clashes, which started overnight, come as Crimea is about to hold a referendum on Sunday, which will decide whether it should break away from Ukraine to join Russia.

Ukraine’s Interior Minister Arsen Avakov said that the shootout that started Friday night and continued till dawn is under investigation. According to Russian state news agency Itar Tass, the shots were fired from the offices of the far-right Ukrainian nationalist group, Right Sector. The police reportedly said that pro-Russians chased the gunmen who had opened fire on them to the headquarters of a far-right group called Patrioty Ukrainy (Ukrainian Patriots) – allies of Right Sector, which was at the heart of the Kiev anti-government protests. By the time the police arrived at the location, six were injured and two had killed, according to Agence France-Presse.

The latest clashes in Kharkov come a day after a 22-year-old man was killed the eastern city of Donetsk, when 2,000 pro-Russian protesters attacked a pro-Ukrainian group rallying there. Ukraine's acting president Oleksandr Turchynov on Friday blamed the fatal clash on thugs "sent in" from Russia.

U.S. Secretary of State John Kerry, in a meeting with Russian Foreign Minister Sergei Lavrov, failed to avert the ballot or win Russia’s assurance that Moscow will delay incorporating the Black Sea region that Ukraine only received in 1954, as a "gift" from then-Russian President Nikita Khrushchev in 1954.

Lavrov had reportedly assured Kerry that Moscow "has no, and cannot have, any plans to invade the southeast region of Ukraine" though it will remain stationed on the Black Sea peninsula but he hinted that Russia would like to have Crimea under its control, AFP reported.

"Everyone understands -- and I say this with all responsibility -- what Crimea means to Russia, and that it means immeasurably more than the Comoros [Archipelago] for France or the Falklands for Britain," Lavrov reportedly said, according to AFP.

According to Interfax Ukraine, a local agency, Ukraine’s Prime Minister Arseniy Yatsenyuk has stated that the country has formulated an elaborate plan on how to sort out the Crimean issue but Russia has refused to consider it. U.S. and Germany have been repeatedly stressing that an invasion by Russia would lead to consequences. A local German newspaper reported Friday that the joint list between U.S. and European Union issued a travel ban on Russians including leading politicians like Defense Minister Sergei Shoigu, Kremlin’s chief of staff and a close ally to Russian President Vladimir Putin, among others.