At least 25 people were killed when a suicide car bomb exploded at a checkpoint close to a US base in southeastern Afghanistan on late Sunday.
Afghan officials said another 10 civilians were injured during the powerful blast near Camp Chapman in the city of Khost, where both Afghan and international troops have been stationed.
Khost police chief Faizullah Ghairat said the bomber detonated the explosives as his car was stopped, adding all the victims were Afghan civilians, including children.
“The number of casualties may increase because some of the wounded are in grave condition,” he said.
Camp Chapman is located near the Pakistani border and is used by the CIA for attacks on the Taliban and Al Qaeda. In 2009, "de-radicalised" Al Qaeda militants killed seven CIA agents in the base, in one of the worst attacks against the US intelligence agency so far.
In the northern Kapisa province, another bomb attack killed at least 10 civilians, Afghan officials also said. No group has yet claimed responsibility but the officials point to the Taliban, which started a spring offensive last April despite ongoing peace talks.
The Afghan government has negotiated with the Taliban in Qatar, China, Norway and Dubai in recent months to find a way to end the conflict with the group which has resulted in the deaths of an estimated 40,000 civilians since 2001.
In other news, at least two Pakistani troops were killed in a landmine blast on Sunday.
Pakistani officials said five soldiers were also injured in the blast when their convoy struck a landmine in the remote Tirah valley in northwestern Pakistan’s Khyber Agency tribal area, near the Afghan border.
Pakistan's military has been conducting a massive security operation in the volatile area since last October and despite claiming success, attacks continue in the region. During the operation at least 45 Pakistani soldiers and 350 militants have been killed so far, according to the army.