1. In a zone contiguous to its territorial sea, described as the contiguous
zone, the coastal State may exercise the control necessary to:
(a) prevent infringement of its customs, fiscal, immigration or
sanitary laws and regulations within its territory or territorial
sea;
(b) punish infringement of the above laws and regulations
committed within its territory or territorial sea.
2. The contiguous zone may not extend beyond 24 nautical miles from
the baselines from which the breadth of the territorial sea is measured.
Source: UNCLOS