Nepal Protesters Lynch Wounded Policeman

Protesters dragged a wounded police officer out of an ambulance and killed him on Friday in an area of southern Nepal where anger is running high after four demonstrators were shot dead by security forces.

The officer was being taken to hospital after being beaten by protestors on his way to work in the southeastern district of Mahottari when a mob forced the ambulance to stop before dragging him out and torching the vehicle.

The incident came on the same day police shot dead a female protester in Mahottari, where hundreds defied a curfew imposed after three people were also shot dead as they demonstrated against a proposed new constitution.

"A crowd of about 150 stopped and surrounded the ambulance, dragged him out to a field nearby and killed him. The ambulance was torched," a spokesman for the armed police force Pushpa Ram KC told AFP. 

More than 30 people including 11 police officers and an 18-month-old boy have been killed in violent clashes between security forces and protesters against a proposed new constitution that would divide the Himalayan nation into seven provinces.

Anger is running particularly high in the country's southern plains, where historically marginalized communities including the Madhesi and Tharu ethnic minorities say the new internal borders will limit their political representation.

The latest incident comes after three demonstrators were shot dead when police opened fire during a protest in Mahottari on Wednesday.

The police spokesman said the fate of the ambulance driver and another officer in the vehicle was unknown, although a Red Cross representative who was in the ambulance is safe. 

"We are investigating what happened," he said.

Nepal's human rights commission on Friday urged both sides to engage in peaceful dialogue and said the government should withdraw troops deployed to try to maintain order.

Work on a new national constitution began in 2008, two years after the end of the Maoist insurgency that left an estimated 16,000 people dead and brought down the 240-year-old Hindu monarchy. 

But negotiations faltered over the issue of internal borders and the resulting uncertainty left Nepal -- one of the world's poorest countries -- in political limbo.