SEOUL, Oct 19 (Reuters) - North Korea issued its most strident warning to the South in months on Friday when it threatened to open fire on South Korean territory if anti-Pyongyang leaflets were sent over from South Korean territory.

It said that if leaflets were dropped on Monday a “merciless military strike by the Western Front will be put into practice without warning”, according to state news agency KCNA.

Leaflets are sent across the border via by campaigners against North Korea, but not by the government in Seoul.