A bomber blew himself up near a district chief's house in western Afghanistan (search) on Tuesday, killing only himself, officials said. No other casualties were reported.

The unidentified man detonated explosives he was carrying about 160 feet from the official's house in the city of Herat (search), capital of Herat province, said provincial police chief Mohammed Ayub Salangi.

Dad Mohammed Rasa (search), an Interior Ministry official, confirmed the attempted attack.

The district chief was sitting on a motorcycle near his house in downtown Herat at the time of the explosion early Tuesday, Salangi said.

The attack comes amid an unprecedented spate of bloodshed that has left more than 700 people dead in three months and threatens to sabotage three years of progress toward peace in Afghanistan that followed a U.S.-led invasion to oust the hardline Islamic Taliban regime.

The violence has been concentrated in Afghanistan's south and southeastern provinces. Herat has been spared much of the bloodshed and is considered one of the country's safest cities.

Suicide attacks are relatively unusual in Afghanistan.

The last such attack was on June 1, when a suspected Al Qaeda suicide bomber killed 20 people at the funeral of an anti-Taliban cleric in the southern city of Kandahar, one of the worst terror attacks here since the ouster of the Taliban in 2001.