JALALABAD, June 26: A bomb killed two women working for the UN-Afghan electoral body and wounded nine female poll workers and two children on Saturday, in one of the worst attacks yet on preparations for the elections.

The Taliban swiftly claimed responsibility for the attack, which was a further setback for President Hamid Karzai's efforts to bring peace to a country US President George Bush has described as a role model for Iraq.

The blast in the eastern city of Jalalabad destroyed a bus taking the Afghan women to register female voters for the polls scheduled for September, which the Taliban and allied militants have vowed to disrupt.

"We did this because we warned people not to get involved in the election process," Taliban spokesman Abdul Latif Hakimi said. "This only strengthens the foundations of the American-backed government."

He said the guerillas had also killed two US Marines in an ambush in the eastern province of Kunar on Thursday night but had released a Turk kidnapped in March while working on a reconstruction project - partly because he was a Muslim.

UN spokesman Manoel de Almeida e Silva said the Jalalabad attack was probably aimed at discouraging women from voting. He said movement of female staff was being temporarily restricted.

"They will not reach their goal," he added.

About 4.5 million of nearly 10 million eligible voters have registered, but the process has been slowed in the south and east by violence. Female registration has lagged, partly due to problems recruiting female workers needed to register women.

Jalalabad police chief Mohammad Younis Noorzai said the bomb was planted inside the minibus. "It was a locally hired van and we have arrested the driver, who was also wounded," he said.

The UN spokesman said two women were killed while three were in critical condition, along with a child who was accompanying his mother. Nine women suffered lighter injuries.

UN Special Representative Jean Arnault said he was "profoundly outraged".-Reuters