Kabul, Afghanistan ? A bomb ripped through a minibus carrying Afghan women election workers and children Saturday morning outside the eastern city of Jalalabad, killing two women and injuring 13.

The bus driver was arrested, and an investigation is under way, officials said.

A man saying he was a spokesman for the Taliban called The Associated Press and took responsibility for the bombing. The Taliban and other insurgents have announced plans to disrupt the country’s first elections, which are scheduled for September.

Female election workers will temporarily be restricted from moving around the country, said Jean Arnault, the United Nations special representative in Afghanistan. “The registration of women continues wherever possible,” he said in a statement, adding that he was “profoundly outraged” by the bombing.

Women comprise about one-third of the 4.5 million people who have registered to vote so far in Afghanistan.

President Hamid Karzai called the bombing “anti-Islamic” and said it aimed to spread poison in the country.

“The enemies of peace and stability are jealous of the fact that people are very eager to take part in voter registration, especially the residents of Nangahar province,” Karzai said.

In Nangahar province, where Jalalabad is the capital, about 600,000 people have registered, and 210,000 of those are women. Only Kabul province has registered more voters.

In Afghanistan, the sexes are traditionally segregated, whether at meals or in school. Women sign up female voters, and men sign up male voters. In some areas, female workers even knock on doors to convince women inside their homes why they should vote.

“Their killers probably wanted to stop this momentum towards broad female participation,” Arnault said. “They will not reach their goal.”