Indian Prime Minister Narendra Modi branded Pakistan a "mother-ship of terrorism" at a summit of the BRICS nations on Sunday, testing the cohesion of a group whose heavyweight member China is a close ally of its South Asian archrival.

Modi's remarks to a meeting of leaders from the BRICS — which include Brazil, Russia, China and South Africa — escalated his diplomatic drive to isolate Pakistan, which India accuses of sponsoring cross-border terrorism.

Tension between the nuclear-armed neighbors has escalated since a Sept. 18 attack on an army base in Kashmir, near the disputed frontier with Pakistan, killed 19 Indian soldiers in the worst such assault in 14 years.