KABUL (AP) – A Taliban ambush in northwestern Afghanistan killed four policemen early Sunday, while militants killed five other people at the eastern border near Pakistan, officials said.

Militants attacked a police security post in northwestern Faryab province, sparking a one-hour battle that killed four police, said Khalil Andrabi, the provincial police chief.

A second Taliban attack in the eastern province of Paktika killed the police chief in Sarhawza district, while militants elsewhere in Paktika ambushed a truck of private security guards, killing four of them, said Hamidullah Zhwak, a spokesman for the governor.

Militants have stepped attacks in Afghanistan. President Barack Obama is sending 21,000 additional troops this year to help increase security in regions where the Afghan government has little control.