SEOUL (Reuters) - North Korea said on Wednesday it would respond firmly if South Korea continued to hold five people who had drifted south in a fishing boat, including three believed to be seeking asylum.
The spat comes amid political tension between the rival Koreas that remain technically at war under a truce ending the 1950-53 conflict and a slew of verbal assaults from the North against the South Korean government.
The North, in a message relayed by its Red Cross chief to a counterpart in the South, accused South Korean authorities of trying to coerce the five into defecting, calling it "a cowardly act of crime against humanity".
"The South side must stop using hackneyed trickery that will fool no one and unconditionally return our citizens," the message signed by the Red Cross chief, Kang Su Rin, and carried by the North's external propaganda website Uriminzokkiri said.
"If all our citizens are not returned promptly and continue to be held, we will take a firmer responsive measure."
The South's Unification Ministry, which handles ties with the North, said on Tuesday that it had received a demand from the North for the return of the five, but it would respect the wish of the three who requested asylum on humanitarian grounds.
The other two who expressed a wish to return will be handed over soon at the Panmunjom truce village on the border, the ministry said.
The five had drifted south in the waters off the Korean peninsula's east coast in a vessel that was badly damaged and taking in water, it said.
In June, North Korea repatriated a South Korean married couple held for what it said was illegal entry.
But four other South Korean citizens are known to be held by the North, including two men who confessed to having spied for the South, and a 21-year-old New York University student who is a U.S. green card holder.
(Reporting by Jack Kim; Editing by Jeremy Laurence)