Tensions remain high with arch-rival India after the nuclear-armed neighbors launched tit-for-tat airstrikes in February following a suicide bombing in Indian Kashmir which was claimed by Pakistan-based militants.
What did the Pakistan militants claim?
The Pakistan militants "claimed" responsibility for the suicide bombing.
The writer of the article uses this construction because it avoids saying that the militants actually carried out the attack. The sentence means that the Pakistan militants approve of the attack, and that they say they were the ones who did it (which may not even be true).
