A suicide bomber said to be aged 12 has killed four people in east Afghanistan.
It was one of several attacks a day after the Taliban declared a new campaign to attack foreign troops, Afghan security forces and government officials, the BBC reports.
A boy wearing an explosive jacket blew himself up in a market in Paktika province in the east of the country, killing four people including a local official. The governor of the province said the suicide bomber was 12 years old.
A BBC correspondent says by one count, more than 150 would-be suicide bombers between the ages of 13 and 17 have been intercepted by the Afghan security forces.
In Ghazni province, a gunman opened fire at a police checkpoint, killing two police officers, and a bicycle bomb near the city's police station wounded civilians.
Thousands of extra soldiers and police have been deployed in Kandahar and other cities.
A gradual withdrawal of foreign combat troops is due to begin in July as part of a handover to Afghan security forces.
