South Korea’s intelligence agency is to continue to hold 13 North Koreans at the heart of a bitter dispute between the rival countries, with Pyongyang accusing Seoul of abducting the group from a restaurant, according to an official.

Intelligence officers want longer to question the group of 12 waitresses and a manager at a North Korea-run restaurant in China, who arrived in Seoul in April.

South Korea says they defected of their own free will, while the North claims they were abducted.

The move came ahead of a South Korean court’s decision to delay a request for a hearing by a group of lawyers. The lawyers want to question the group about whether they defected freely, after the intelligence agency refused to present them in court.

“The director of the National Intelligence Service has decided to extend their protection,” a South Korean official said, citing concerns for their safety and a law covering the resettlement of North Korean defectors.

The government official, who requested anonymity, accused the North of carrying out a “propaganda campaign” over the status of the group, saying this had been a factor in the decision to prolong their questioning.

The Seoul central district court said it had ruled to delay a petition filed by Minbyun, or Lawyers for a Democratic Society, seeking to question the women.

“We don’t think it is possible to make a decision without confirming the restaurant workers’ intent in this case,” Chae Hee-joon, a lawyer for Minbyun, told reporters, adding that Minbyun had filed a recusal motion to the court, citing the women’s absence.

The National Intelligence Service has said it will not bring the alleged defectors to the court and only their legal representatives will attend the questioning.

The agency has held the group since they arrived in South Korea on 7 April at a facility it runs on the southern outskirts of Seoul. More than 1,000 people from North Korea stay at the facility each year in the initial stages of defection. For up to 180 days, they are screened and questioned on their lives in the North.

The agency’s decision to extend the women’s stay means they will not be moved to a resettlement complex where defectors spend 12 weeks learning about life in the South.

South Korea is technically at war with the North, because the 1950-53 conflict between the two countries ended in an armistice, not a peace treaty.