Bombs killed 15 people and wounded dozens more including an election candidate in Pakistan on Tuesday, raising to more than 100 the death toll from attacks on the campaign for Saturday's polls. The attacks took place in the northwestern town of Hangu, a flashpoint for violence between Sunni and Shiite Muslims, and in the northwestern district of Dir, where Pakistani troops crushed a Taliban-led insurgency in 2009.

At least 15 people were killed and 70 injured in a bomb explosion Monday in a public meeting in a Pakistani tribal area bordering Afghanistan, police and administration officials said. They said a planted device went off during an election campaign meeting held by the Jamiat Ulema Islam-F party at a religious school in Kurram Agency bordering Afghanistan's Paktika Province. The explosion occurred a few meters from the main platform as the participants were dispersing.

Cross-border clashes broke out Monday between Afghan and Pakistani security forces for the second time in days, escalating tensions between Kabul and Islamabad, officials said. Ties between the fractious neighbours have become increasingly strained despite renewed efforts last month from US Secretary of State John Kerry to get them to work more closely on peace efforts in Afghanistan.

Pakistan summoned the most senior Afghan diplomat in the country Thursday to protest against cross-border fire, which officials say wounded two Pakistani soldiers and killed an Afghan guard. It was the latest clash to underline strained ties between the fractious neighbours, which have worsened in repeated months despite Western efforts to get them to work more closely on peace efforts in Afghanistan. The two nations accused each other of starting the firing on the border, which is a crucial battleground in the fight against Taliban militants who operate in both countries.