Madang, like much of Papua New Guinea, has had safety issues particularly related to crimes such as bag snatching and armed robbery in the city. It's advisable to avoid walking in isolated areas especially after dark as well as avoid direct engagements with locals as it may lead to uncomfortable situations. Arranging for private transportation rather than relying on public transport can lend an added layer of security. Be sure to closely guard your personal belongings and valuables at all times, and stick to tourist-friendly areas when possible.