Indonesia's economy stumbled in the first quarter, with growth coming in below expectations, amid signs the government's stimulation efforts may be falling short.

"The Indonesia economic outlook has rapidly turned from encouraging to problematic," Glenn Maguire, chief economist for Asia-Pacific at ANZ, said in a note Tuesday. "Government spending is leading the slowdown and must be activated efficiently and coincidentally to all the economy to base and for growth to recover," he said. "We do not have a high degree of confidence that sequential growth momentum has indeed bottomed in the first quarter."