Juba, April 26 : The recent intensified fighting in South Sudan's Unity and Upper Nile states between the parties to the 2018 revitalised peace agreement is undermining efforts to achieve a permanent ceasefire, monitors said. Asrat Denero Amad, Chairperson for the Ceasefire Transitional Security Arrangement Monitoring and Verification Mechanism (CTSAMVM), said that the ongoing tension in Unity and Upper Nile states since February 11 are threatening peace, reports Xinhua news agency. "There is tension in Unity state since Mirmir cantonment site was overrun on February 11, by Kit-Gwang elements and armed youth reportedly instigated by the Koch County Commissioner," said Amad during the CTSAMVM technical committee meeting in Juba, the capital of South Sudan. He disclosed that attacks by hold-out opposition group National Salvation Front (NAS) led by Thomas Cirilo Sawaka continue to take place in Central and Western Equatoria states. Amad observed that tensions remain in Tambura county of Western Equatoria state where fighting since 2021 displaced nearly 80,000 civilians. "The situation in the counties of Maban, Maiwut, and Longechuk in Upper Nile state also remains tense following the fighting in these areas since February. CTSAMVM has received reports of at least eight alleged incidents, including the ambush and destruction of two Medicines Sans Frontier vehicles near Yei on February 28," said Amad. Martin Abucha, a member of First Vice President Riek Machar's Sudan People's Liberation Army-in Opposition, also called for a probe into these violations across the country. /IANS