1.   Each side blamed the other for the sharp escalation of their eight-day confrontation in a rich crab fishing ground that both Koreas claim as their territorial waters.

2.   North Korea wants the sea border to be moved further south, which would allow it access to rich crab and fishing waters.

3.   North Korean warships have been sailing in and out of rich crab fishing areas in the disputed waters since Tuesday.

4.   Seven North Korean warships sailed into what both Koreas claim as territorial waters, a rich crab fishing ground, but then withdrew after sunset.

5.   The area is a rich crab fishing ground controlled by South Korea.

6.   The area is a rich crab fishing ground claimed by both Koreas as their territorial waters.

7.   The clash occurred in a rich crab fishing area claimed by both Koreas as their territorial waters.

8.   The contested waters, a rich crab fishing zone, are claimed by the rival Koreas as their territorial waters.

9.   The area is a rich crab fishing ground.

10.   The disputed area is a rich crab fishing ground.