Lviv Mayor Andriy Sadovyi, in his Telegram page Tuesday, says "explosions were heard in Lviv" and is urging residents to stay in shelters.

    Part of the western Ukrainian city is suffering from power outages following the blasts, he added.

A video purportedly showing the aftermath of the explosions, which was posted on Twitter, shows a large cloud of black smoke rising into the sky.

    In Lviv, car alarms went off after the blasts and emergency sirens could be heard, the Associated Press reports.The city on Monday had a news conference with the country’s top U.S. diplomat, discussing how America planned to reopen its diplomatic presence in Lviv.