The deceased were identified as Yahya and Abu Thahir, both hailing from Palakkad, and had reportedly joined Islamic State and Al Qaeda, respectively, police said.
They were among the 21 people, including women and children from Kerala, who had travelled to the Middle East and went missing in 2016.
17 of them were from Kasargod and the rest from Palakkad.
Police said they received an information on Saturday night about the death of Thahir in Syria.
A message received by a social worker in Kasargod said: ‘Yahya has been martyred while fighting in Afghanistan’.
The sender of the message, Asfak, said Yahya was ‘martyred’ in the US attack.
‘He was killed while fighting the US forces,’ the message read.
It, however, did not specify when he was killed.
A fortnight ago, one Murshid Muhammed from Padna in the district was killed in a drone attack in Afghanistan.
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