An explosive went off in an apartment building entrance in Monaco, wounding three people, reportedly including a Ukrainian tycoon with ties to Russia. That's according to the exclusive country's chief prosecutor. A search was underway Tuesday for a suspect who fled on foot. Prosecutor Stéphane Thibault said the motive was unclear. Media reports identified Ukrainian construction tycoon Vadym Yermolaiev as being among the injured. Ukrainian news site Ukrainska Pravda said he was targeted by Ukrainian sanctions in 2023 for ties to Russia. A woman and a child were also hurt.