Kathmandu: Nepal's top Madhesi leader Rajendra Mahato, who had suffered injuries in a clash with police during a sit-in last week, was today airlifted to Delhi for further treatment as his condition did not improve.

The 57-year-old Chairman of Sadbhawana Party, one of the four Madhesi-based political parties that have launched an agitation in southern Nepal under the banner of United Democratic Madhesi Front, has left for New Delhi for medical treatment, according to Vice president of the party Laxaman Lal Karna.

The senior Madhesi leader was initially airlifted from Dharan, where he was undergoing treatment for the past week, to the capital Kathmandu, from where he was again airlifted to Delhi.

The leader, who had sustained injuries including on head during a clash between the largely Indian-origin Madhesis and police at Biratnagar-Jogabani border check-point on December 26, was flown to Delhi as his health condition could not improve much even after staying in the ICU for some time,

Karna told PTI.

He was injured during baton charging by the police as he was leading a group of Madhesi cadres for a sit-in to blockade movement of vehicles in the border area.

The police had baton charged the agitators and fired teargas shells to disperse them. The senior Madhesi leader had spent over a week while undergoing treatment at a local hospital in Biratnagar and Dharan-based B P Koirala Institute of Health Sciences.

Mahato's blood pressure and sugar level were also found to be higher than normal.

He had fallen unconscious for some time while undergoing treatment, sources close to him said.

Mahato, along with three other senior Madhesi leaders, had travelled to Delhi for political consultation last month and held talks with senior Indian leaders including External Affairs Minister Sushma Swaraj.

Madhesis have resorted to aggressive protests after Mahato sustained injuries and have demanded action against the security personnel involved in the incident.

Madhesis are agitating over the new Constitution demanding more representation. They are also protesting division of their ancestral homeland under the seven-province structure and have led an ongoing blockade of key border trade points with India.