Consider the following statements regarding the Inner Line Permit (ILP) System:

1. It is a travel document issued by the Government of India for foreign nationals wishing to visit protected areas in India.

2. It  is applicable only to Indian citizens traveling to border areas of India.

3. Nagaland, Manipur, and Sikkim are currently under the ILP system.

4. It applies only to tourists visiting these areas.

Which of the above statements is/are correct?