Eighteen dead and dozens injured in two attacks in Afghanistan

An Afghan security personnel inspects vehicle wreckage at the site of a suicide attack in Kandahar province 31 August 31, 2013. A suicide bomber detonated an explosive in an attack that killed 18 (Reuters)

A suicide bomber has killed 18 people after detonating explosives close to a police checkpoint in southern Afghanistan in one of two attacks occurring within 24 hours of each other.

In a second attack a Nato service member was killed by insurgents in the country's east, a military statement confirmed.

The Nato service member died in "a direct fire attack by enemy forces in eastern Afghanistan" on Saturday, according to a statement from the military alliance. The statement did not give any further details on the person killed.

Javed Faisal, a spokesman for the provincial governor, initially said the suicide bomber was in a car that was being searched by police, but later said new information indicated the bomber had been on foot. Along with the branch building of the New Kabul Bank, several small shops and vehicles were damaged.

No group immediately claimed responsibility for any of the attacks, but Taliban fighters have escalated their activity as US-led foreign forces reduce their presence in the country, having handed over primary responsibility for security to Afghan troops.

Witness Shah Wali said he had just stepped out of a taxi to enter the bank when the bomb was detonated "I saw a man and a vehicle on the road, and while I was fixing my shoelaces I heard a loud explosion. I don't know if it was the vehicle which exploded or the man standing there," Mr Wali said.

Another 12 people were killed in an ambush involving a roadside bomb in Sangin district in Helmand province, also in the south, on Friday evening, said Omer Zwak, a spokesman for the provincial governor. Sangin is the scene of an ongoing operation by Afghan forces against the Taliban.

Mr Zwak said 11 men and one woman died in the attack, and that the vehicle also was hit by several rounds of gunfire. Such attacks typically target security forces, but, in this case, "the victims are all civilians and had no link with the government," Mr Zwak said.

Afghan and coalition officials have warned that the Taliban would intensify the tempo of their attacks following the Muslim holy month of Ramadan, as they try to take advantage of the two or three months left of good weather before the harsh Afghan winter sets in. The traditional fighting period lasts from March until the end of October.

Additional reporting by Associated Press