KABUL - Two remote-controlled bombs attached to bicycles exploded about 30 minutes apart Saturday in two parts of a city in eastern Afghanistan, killing four people and wounding more than 30, local officials said.

The Afghan Ministry of Interior said two suicide attackers were responsible, but local authorities said they could not find evidence that insurgents blew themselves up at the two sites.

Ghulam Aziz Ghranai, the police chief in Laghman province, said the first morning explosion occurred as vehicles were waiting to be searched at a police checkpoint on a road leading into the provincial capital of Mehtarlam.

Deputy provincial governor Edayutullah Qalanderzai, who was at a local hospital, said a woman, a child and an elderly man were killed and 25 others were wounded, including one Afghan policeman.

The second explosion, which killed one and injured eight others, occurred about a half hour later inside the city less than a mile from the first blast, Qalanderzai said.

President Hamid Karzai condemned the attacks in Mehtarlam, about 100 kilometres east of Kabul.

Separately, the Afghan government reported that a senior Taliban commander was killed in an airstrike Saturday in Nad Ali district of Helmand province in the south. The commander was known to have planned bombings and suicide attacks in the area, according to a government statement.

On Friday, Afghan and coalition troops in eastern Afghanistan captured an insurgent believed to have planned suicide attacks for al-Qaida, the Taliban and the al-Qaida linked Haqqani network. The troops tracked the insurgent in charge of the suicide operations in the province to a compound in Khogyani district of Nangarhar province where he was apprehended.