Arabic speaker here. This is weird because in Arabic there are two words that can both be spelled as "shahid" in English but they are pronounced differently and spelled differently in Arabic. Witness is generally spelled as شاهد which is pronounced as Shaaa-Hed. شاهد can litetally mean "to see or to watch something". Martyr is شهيد which is pronounced like Shahiiiid.

But it's complicated too because the plural "shohadaa" is the same for both these words so it can mean "witnesses" or "martyrs".

The article is using two words as if they are one word used differently. They are two words that have the same plural form.