vṛtram - Vṛtrāsura; abhyadravat - attacked; śatrum - the enemy; asura-anīka-yūthapaiḥ - by the commanders or captains of the soldiers of the asuras; paryastam - surrounded; ojasā - with great force; rājan - O King; kruddhaḥ - being angry; rudraḥ - an incarnation of Lord Śiva; iva - like; antakam - Antaka, or Yamarāja.

My dear King Parīkṣit, as Rudra, being very angry at Antaka [Yamarāja] had formerly run toward Antaka to kill him, Indra angrily and with great force attacked Vṛtrāsura, who was surrounded by the leaders of the demoniac armies.