PORTSMOUTH At least 15 valuable bronze vases have been stolen this month from grave markers at Evergreen Memorial Park, police said Friday. The first reported theft at the cemetery occurred between April 7 and 9, a news release said. A relative found five vases missing from the markers of family. The second reported theft occurred between April 10 and Wednesday, when five vases went missing. A third theft of five vases was reported Tuesday, those between April 6 and 8. Replacement value for each vase ranges from $300 to $350, the release said. Detectives say there may be more vases that have been removed from the cemetery, which is in the 3300 block of High St. They ask anyone who has family buried there to check and report thefts to police at 393-5300.