KANDAHAR - A suicide car bomber blew himself up next to a police truck bringing a southern Afghan official to work early Monday, killing six children nearby, officials said.

The blast went off at about 9 a.m. local time near a market area in Dand district to the west of Kandahar city, according to the official who was targeted -- district government chief Ahmadullah Nazak.

"I dropped down. Then I heard a second explosion," Nazak said. "It hit our car, but it didn't injure me." The Interior Ministry originally said five children were killed in the blast, and Nazak said a sixth had died by early afternoon.

A bodyguard who was driving with Nazak was wounded, he said.

No one immediately claimed responsibility for the attack, though it fits the pattern of Taliban attacks targeting government officials in the south. As additional U.S. forces have poured into southern Taliban strongholds in Kandahar and Helmand provinces, insurgents have mounted a counter-campaign of bombings and assassinations aimed at those affiliated with the Afghan government.

Militants attacked a second government official in the east the same day. The convoy of a presidential adviser was hit by a remote-controlled bomb hidden in a rickshaw as it was driving through Jalalabad city, said Ghafar Khan, a police spokesman in Nangarhar province. The adviser -- Wahidullah Sabaoun -- was wounded but not seriously, Khan said.

In eastern Nuristan province, NATO and Afghan troops attacked two villages that had been held by Taliban fighters, killing more than 30 insurgents as they secured the Bachancha and Badmuk villages, NATO said in a statement. Two Afghan soldiers were killed, NATO said.

Afghan officials in Nuristan corroborated the account.

The attacks were part of an ongoing effort to secure the area around the village of Barg-e-Matal which has shuttled between government and insurgent control in recent months.

Elsewhere, coalition and Afghan troops arrested a senior commander of the Haqqani group, an al-Qaida-linked wing of the Taliban based in neighbouring Pakistan, the NATO-led command said in a statement.

The commander, whose name was not released, was apprehended in Khost province along with "several" suspected insurgents and was believed to be planning attacks in connection with the Sept. 18 parliamentary elections, the statement added.