The Taliban killed at least 10 people and critically injured a local police chief in western Afghanistan's main city on Monday with a remote-controlled bomb hidden in a trash can, officials said.

The bomb was set on a crowded street near a fruit market in Herat. It killed 10 civilians and two police, according to Noor Khan Nekzad, a spokesman for the Herat provincial police.

The attack appeared to target the police chief for nearby Injil district who was driving into town, said Raouf Ahmedi, the top police spokesman in western Afghanistan.

He said the district chief, Mohammad Issa, was being transferred to a NATO-run hospital in critical condition.

Ahmedi said only 10 people were killed in the blast, including a woman, a young girl and six men. There was no immediate explanation for the different police counts. At least 30 people were injured in the blast, which blew windows out on a 100-meter (yard) radius, he said.

A Taliban spokesman, Qari Yousuf Ahmadi, said the group had targeted the police chief.

The bombing in the comparatively calm Western city of Herat highlighted the volatile situation across the country as Afghanistan braces for presidential and local elections later this month.

Some 101,000 NATO and U.S. troops are deployed to secure the country. This includes a record 62,000 U.S. troops, more than double the number a year ago but still half their strength in Iraq. President Barack Obama has increased the U.S. focus on Afghanistan as the Pentagon begins pulling troops out of Iraq.

Nine troops have been killed in fighting or bombings this month, including three Americans on Sunday and three on Saturday, along with two Canadians and one French.

July was the deadliest month for international troops since the 2001 U.S.-led invasion to oust the Taliban government for sheltering al-Qaida leader Osama bin Laden, with 74 foreign troops, including 43 Americans, killed.

Roadside bombs have become the militants' weapon of choice in Afghanistan, and the number of such attacks has spiked this year.

U.S. troops say militants are now using bombs with little or no metal in them, making them even harder to detect. The Taliban are also planting multiple bombs on top of one another and planting several bombs in one small area.

U.S. commanders have long predicted a spike in violence in Afghanistan this summer, the country's traditional fighting season, and Taliban militants have promised to disrupt the country's Aug. 20 presidential vote.