South Korea said it fired warning shots at a Russian military aircraft on Tuesday after it violated the country's airspace off its east coast. 

Russian President Vladimir Putin arrives in Rome Thursday for a lightning visit including talks with the pope and Italy's populist government, which has called for an easing of sanctions despite Moscow's ongoing crisis with the West.

Russia and China on Tuesday blocked an American initiative that aimed to halt fuel deliveries to North Korea, which Washington accuses of exceeding its annual ceiling for 2019, diplomatic sources said.

Moscow and Beijing said more time was needed to study the US request, which was backed by 25 UN members including Japan, France and Germany, according to the sources. 

At least 19 people were injured in a blast at a major explosives plant in central Russia on Saturday, the Interfax news agency reported, citing the local health ministry. 

Russia will not immediately raise oil output after the United States ends sanctions waivers for buyers of Iranian crude in May, President Vladimir Putin said Saturday.

The United States announced this week that, in a bid to reduce Iran's oil exports to zero, it would from May 2 end US waivers that countries such as India, China, South Korea and Turkey currently have on buying Iranian crude.

Russian President Vladimir Putin said Saturday Moscow was "thinking" of making it easier for all Ukrainians to obtain Russian citizenship after the Kremlin moved to grant passports in the country's separatist east, causing uproar in Kiev.  

North Korean leader Kim Jong Un left the Russian city of Vladivostok on Friday after a summit with Russian President Vladimir Putin where the two vowed to pursue closer ties.

North Korea's close relationship with the Soviet Union cooled in the 1990s under a new Russian power, but were revived in the 2000s as Moscow sought support amid a new standoff with the West. 

Russian President Vladimir Putin and North Korean leader Kim Jong Un vowed to seek closer ties as they met face-to-face Thursday for the first time.

President Vladimir Putin on Wednesday signed a decree making it easier for people living in eastern Ukraine's separatist territories to obtain a Russian passport.

The decree, published on the Kremlin website, is aimed at residents of the unrecognised Donetsk and Lugansk republics that broke away from Kiev in 2014 and are governed by Moscow-backed rebels.