To wit:
2 petrol bombs [Grenades, DV 10P (Fire), AP –2, Blast –2/m]
Note: Their petrol bombs detonate immediately on impact, and generate smoke like smoke grenades as well as causing Fire damage to those in Blast range.
I'm surprised the AP is -2 instead of -6, as it is in the Core rulebook (p. 171).
I would also use the ongoing fire damage from the Core book as well. (DV 3, increasing by 1 each Combat Turn until the item is destroyed or the fire is put out.)
