Tens of millions of Indonesians will vote on Wednesday in regional elections seen as a gauge of President Joko Widodo's prospects for re-election next year in the world's third biggest democracy.

Pakistan's military brushed off speculation on Monday that a new US strategy for neighbouring Afghanistan could include taking a stronger line against Islamabad, insisting the country has done all it can to tackle militancy.

A bomb exploded next to a convoy of the deputy chairman of the Pakistan Senate on Friday in the violence-plagued province of Baluchistan, killing at least 25 people, officials said.