Do I need to collect my luggage on a layover in Singapore?

Question

I am flying from Bali to Mashhad. I bought the ticket from Qatar airways. My flight is:

1. Bali → Singapore (operated by Indonesia Airways)

2. Singapore → Doha (Qatar Airways)

3. Doha → Mashhad (Qatar Airways)

Do I need to collect my bag in Singapore as they are under different airlines, though I booked it together?