1.   But the deal was put on hold when a North Korean submarine infiltrated into South Korea last September.

2.   But progress on carrying out the agreement suffered a setback when a North Korean submarine infiltrated South Korea in September.

3.   But work has been delayed last September when a North Korean submarine infiltrated into South Korea, a key financier of the project.

4.   Its departure has been delayed after a North Korean submarine infiltrated South Korean waters in September.

5.   Progress on the agreement suffered a setback when a North Korean submarine infiltrated South Korea in September.