A man who claimed he had a gun robbed an Omaha gas station Wednesday night, Omaha police said in a news release.The clerk at the Mega Saver near 42nd and Grover streets told police the robber walked in just before 9 p.m. The man wore a mask and showed the clerk a note saying he had a gun and demanded money. The suspect left after getting some cash.Anyone with information is asked to contact Omaha Crime Stoppers at 402-444-STOP (7867) or by using the P3 Tips mobile app.