KIEV, April 25 (Reuters) - Seven people were injured overnight at a pro-Ukrainian checkpoint near Ukraine's Black Sea port of Odessa when an explosive device blew up, local police said on Friday.
Residents in the town have built several such checkpoints near the town aimed at stopping pro-Russian separatists entering from Moldova's breakaway territory of Transdniestria.
"It was an explosive device. It happened at around 4 a.m. (0100 GMT) at a checkpoint set up by a local self-defence organisation," a spokesman for the regional police told Reuters by telephone.
Interfax news agency quoted witnesses as saying a bomb was thrown at the checkpoint from a passing car, though this was not confirmed by police.
Transdniestria, home to Russian peacekeepers and Russian troops guarding a Soviet-era arms stock, declared independence in the early 1990s.
The U.S.-led NATO alliance warned last month of a possible Russian military grab for Transdniestria following Moscow's annexation of Ukraine's Crimea. (Reporting by Pavel Polityuk; Editing by Richard Balmforth and Louise Ireland)