BELGRADE – A French court has ordered former Kosovar Prime Minister Ramush Haradinaj to remain in custody pending an extradition request from Serbia on war crimes in a case that has strained the already fragile ties between Belgrade and Pristina.

A court in Colmar in eastern France on January 5 ordered Haradinaj, a former KLA commander during Kosovo’s 1998-99 war, to remain in custody rather than be released under judicial supervision following his arrest by French police a day earlier.

Haradinaj’s Alliance for Kosovo’s Future (AAK) party told RFE/RL’s Balkan Service on January 5 that the decision to keep him in custody is “unacceptable,” echoing denunciations from top officials in Pristina.

Serbia accuses Haradinaj of committing war crimes in Kosovo.

His arrest upon arrival at an airport in eastern France on a flight from Pristina has triggered outrage in Kosovo, where the government called the Serbian charges “illegal, unfair, and tendentious.”

Kosovar President Hashim Thaci wrote in a January 4 Facebook post that Haradinaj’s detention is “unacceptable in every way” and that the government is using “all available mechanisms” to secure his freedom.

Speaking to reporters in Belgrade before the French court’s decision on January 5, Serbian Prime Minister Aleksandar Vucic pledged that Serbia would continue to press for Haradinaj’s extradition, saying prosecutors “have numerous pieces of evidence” against him.

“He is accused of so many [crimes] that they are impossible to list,” Vucic said.

In June 2015, he was arrested in Slovenia on a Serbian warrant but was released two days later under diplomatic pressure.

The standoff has prompted calls from some officials and politicians in Kosovo to halt EU-mediated normalization talks with Serbia. Normalized bilateral relations are considered a precondition for Serbia and Kosovo to gain EU membership, which both countries seek.

Edita Tahiri, Kosovo’s minister in charge of the EU-brokered talks with Belgrade, called for Pristina to hit Serbia with reciprocal measures in response to arrest warrants it has issued against Kosovar citizens.

“As long as the Serbian state treats members of the Kosovo Liberation Army (KLA), who fought for this country’s freedom, in this manner, this kind of behavior must have an adequate response from our side,” Tahiri told RFE/RL’s Balkan Service.

“With these primitive acts, Serbia is not only hurting the spirit of the dialogue to have good neighbourly relations, but is proving that it is a destabilising factor in the whole region, and international partners should be seriously worried,” Tahiri told local media.

Reuters cited a security source in Pristina as saying that around 20 Kosovar citizens are currently the subjects of Interpol warrants. Most of these individuals previously served in the KLA, which fought against Serbian forces in the Kosovar war, the source said.

Tahiri said that she has asked the EU to exert its influence on Serbia in order to have the arrest warrants canceled.

Kosovo on January 5 also refused to allow Serbian President Tomislav Nikolic to visit a Kosovar city primarily inhabited by ethnic Serbs to mark the upcoming Orthodox Christmas. Kosovo’s government said the decision was made because Nikolic did not file his entry request on time.

Reuters cited an unidentified Serbian official as saying border-control officials had “harassed” Nikolic’s advance team, preventing them from conducting required security checks.

“The visit will not proceed as planned. This is likely related to the Haradinaj arrest,” Reuters quoted the official as saying.