Consider the following statements regarding the protocol of state mourning in India:

1. State mourning is declared by the President of India in the case of the death of a prominent national leader.

2. During state mourning, the National Flag is flown at half-mast on all Govt. buildings throughout the country.

3. The duration of state mourning is determined by the Ministry of Home Affairs.

How many of the statements given above is/are correct?