|The Laghman attacks come as Nato leaders meet in Lisbon to discuss the transfer of security duties to Afghans [AFP]
Suicide bombers on bicycles have killed four people and wounded 31 others in separate attacks in eastern Afghanistan.
The first bomber detonated his explosives at a police checkpoint in Alisheng district in Laghman province on Saturday, Mohammad Iqbal Azizi, the provincial governor said. The second struck several hundred metres further back.
"We are not sure what the target of the second bomber was but we think he may have detonated his explosives prematurely," Azizi said.
The Taliban claimed responsibility for both attacks through its spokesman, Zabihullah Mujahid, who said the target had been Afghan police and intelligence officials.
The attacks in Laghman come as part of a surge in violence over the past week and as Nato leaders gather for a second day at a summit in Lisbon, Portugal, to discuss plans to start handing over security responsibility to Afghans.
The suicide bombings are also a reminder of the growing military challenge posed by the Taliban and al-Qaeda, as the US administration gears up for a review of its war strategy in December.
Civilian and military casualties in Afghanistan this year have been the highest since the 2001 overthrow of the Taliban, despite the presence of around 150,000 foreign troops.
Violence has even spread to previously peaceful northern provinces.
Exactly a week ago, Taliban fighters, including at least two suicide bombers, attacked a foreign military base in the main airport in Jalalabad in eastern Afghanistan.
The Nato-led force said on Monday five of its troops had been killed over the weekend in a clash with fighters in Kunar province, also in the east. It was the deadliest attack on foreign troops in six months.
At least 2,224 foreign troops have been killed since the start of the war, more than 650 of those in 2010, making it the deadliest year of the war so far.
According to the UN figures, 1,271 ordinary Afghans were killed in the first six months of this year, a 21 per cent jump on the same period in 2009.