The incident took place last night when the cash van was at ICICI bank's ATM at Palam Vihar for delivering cash, a police spokesman said.
The assailants fired at security guard Rampal (42), injuring him severely, following which two persons, Manoj and Jagmohan, hit one of the culprits with the guard's rifle to thwart the robbery but the accused managed to escape with the box containing Rs 10 lakhs from the cash van.
Police said the miscreants ditched the looted box with the entire amount near a petrol pump in the vicinty as they found it difficult to run away with the booty.
However, no arrest were made till late evening in the case, police said.
