Sources said the two BNP men -- Faisal and Mafi -- involved in arms smuggling in the border area had a long rivalry over various issues including domination of the area.

Loyalists of Faisal allegedly assaulted a local woman named Hiratunnesha and mugged her belongings when she was returning home from her father's house on Tuesday night. The victim complained to Mafi about this.

Mafi then asked Faisal to return the woman's belongings snatched by his men.

This led to a gunfight between the two sides that lasted about two hours from 10:00 pm. They exchanged about 100 shots, and the fight stopped when Faisal suffered eye injury.

Ten of the injured were admitted to various health centres. The rest were taking treatment at secret places to evade arrest.

Police rushed to the spot at about midnight and chased the two groups. They fled across the border, sources said.

Faisal's men later ransacked 12 houses of Mafi's supporters.

Tension was prevailing in the area.

Police however claimed the situation was under control.