YANGON, Sept. 12 (Xinhua) -- An unknown fatal disease, which has claimed the lives of seven children in Nanyun township, Myanmar's Naga Self-Administered Zone, is assumed as acute pneumonia related with seasonal flu, Myanmar News Agency reported Wednesday, quoting an announcement of the Ministry of Health and Sports.

The unidentified disease recently broke out in Kwelan village in the township, which is a small village with a population of only over 600 and then spread to Shanhepawkun and other nearby villages.

The ministry attributed the acute pneumonia attack on the children to having not received a pentavalent vaccine following a seasonal flu.

The ministry also put the blame on an uneasy access to the areas, the lack of timely treatment, malnutrition, the lack of general knowledge on health and air pollution caused by cooking on fire at homes for the death of children.

Local health department has sent medical teams to the affected area to provide health care services.

Naga Self-Administered Zone, which lies in Myanmar's northwestern Sagaing region, consists of three townships including Nanyun Township.

In August 2016, an outbreak of measles in the zone caused the deaths of 44 children.