The clash occurred around 11 am and had lasted for about one hour in the LTTE controlled areas off Valaichchenai.
Two female civilians in Panichchankerni were reportedly struck by a mortar attack and rushed to the Batticaloa hospital where one succumbed to her injuries shortly after admission.
The victim had been identified as 45-year-old Kanthi Seri Kali Pillai. The other casualty is being treated at Batticaloa hospital in a critical condition.
According to unconfirmed security intelligence reports five cadres of Wanni group were killed during the clash and many from both sides have been injured.