Dracut police officials said that a TD Bank branch in Dracut was held up at gunpoint for the second time this week on Sunday, and authorities say they think the culprit is the same robber recently dubbed the “Merrimack Valley Bandit” by the FBI. Since February, the robber has hit seven banks in northeastern Massachusetts, including Lawrence, Methuen, Dracut, and Groveland, according to the FBI. Dracut police Lieutenant Stephen Chaput said the robber on Sunday threatened the bank teller with a small semiautomatic handgun before running off with an undetermined amount of cash. Chaput said the same branch was robbed at gunpoint last Monday. Last week, the FBI announced it would award $10,000 to anyone with information leading directly to the bandit’s arrest, noting that the bandit is “considered armed and dangerous.”Jaclyn Reiss can be reached at email@example.com. Follow her on Twitter: @JaclynReiss.