SEOUL (Reuters) -North Korea will launch a military strike immediately in response to any provocation, Kim Yo Jong, the sister and key ally of leader Kim Jong Un, said on Sunday, as it fired artillery shells near its border with the South for the third day in a row. The remarks come after South Korea’s military said the North had fired more than 60 artillery rounds on Saturday near their disputed maritime border, following a similar volley of more than 200 the previous day. North Korea again fired about 90 rounds on Sunday, the South said. The North’s army said they did not pose any threat to …