Hearing of the pitiable condition of King Indra, the demons, following the instructions of their guru, Śukrācārya, equipped themselves with weapons and declared war against the demigods.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
तच्छ्रुत्वैवासुराः सर्व आश्रित्यौशनसं मतम् । देवान् प्रत्युद्यमं चक्रुर्दुर्मदा आततायिनः
tacchrutvaivāsurāḥ sarva āśrityauśanasaṃ matam | devān pratyudyamaṃ cakrurdurmadā ātatāyinaḥ
SB 6.7.18