Nearly 2.5 lakh pilgrims have visited the cave shrine so far.

Six persons have died in the past four days during the ongoing pilgrimage to Amarnath cave shrine in south Kashmir Himalayas, taking the death toll in this year''s pilgrimage to 22, officials said on Saturday.

"Six pilgrims died due to various causes during their pilgrimage to the holy cave shrine of Shri Amarnathji," the officials said here.

Among the dead are 18 pilgrims, two ''sevadars'' (volunteers) and two security force personnel deployed on duty en route the holy cave.

In addition to these, 30 others have suffered injuries due to shooting stones and other causes since the commencement of the pilgrimage on July 1, the officials said.

Deaths due to cardiac arrest triggered by lack of oxygen in the area around the cave shrine have been common over the years, prompting the Shri Amarnath Shrine Board to issue regular health advisories to the pilgrims.

All pilgrims are required to get a fitness certificate issued from a doctor before undertaking the pilgrimage to the shrine located at an altitude of 3,888 metres.

Nearly 2.5 lakh pilgrims have paid obeisance to the naturally formed ice-lingam in the cave shrine in the 19 days of the yatra this year.

The yatra will conclude on August 15.