Shares in Eland Oil & Gas PLC (LON:ELA) lost ground on Friday as it noted what it called "unsubstantiated press speculation" over security incidents in the Niger Delta.
The group's main asset is OML 40 located in the north west of the delta and it also has 40% interest in the Ubima field, also in the area.
"The company confirms that it is not aware of any incidents on its properties and confirms that the company's continuing maintenance and operational activity remains unaffected," it told investors in a brief statement.
There are media reports about a recent escalation of violence in the area. Millitants have launched attacks and the president has cancelled a visit.
Six people were reportedly killed when a boat was ambushed belonging to state oil firm NNPC in the Warri area, while a group the Niger Delta Avengers group said it had attacked two crude pipelines operated by Italy's ENI.
Nigerian militants have said they were responsible for attacks on production facilities operated by Shell and Eni in the region.
Earlier this week, Eland posted sharply higher revenues as production from its acreage in Nigeria climbed almost three-fold in 2015.
The oiler pumped 341,000 bbls of crude oil in 2015, up 195% on 2014, aided by a workover of the Opuama-1 well in November, which led to a 50% increase in gross production from the OML 40 field and a year-end production rate of 4,400 bopd.
Eland shares today shed 15.2% to stand at 26.50p.