Hira Lal, who was attached to the Haryana Railway Police, was deployed at the Shambhu border in view of an ongoing farmers' protest, a police spokesperson said. 

The SI experienced a sudden decline in his health conditions while he was on duty, the spokesperson added. 

Lal was promptly rushed to the Civil Hospital in Ambala, but despite efforts by medical personnel, he died, the spokesperson said. 

Haryana director general of police Shatrujeet Kapur expressed grief over the death of the sub-inspector. 

The Samyukta Kisan Morcha (Non-Political) and the Kisan Mazdoor Morcha have given a "Delhi Chalo" call to press the BJP-led Centre to accept the farmers' demands. 

Farmers from Punjab began their march to the national capital on Tuesday, but were stopped by security personnel at the Shambhu and Khanauri border points between Punjab and Haryana. -- PTI