Militants have stepped up their attacks against Afghan police, killing nine and abducting 11 across the nation in the past two days, authorities said Tuesday _ charging that poison was involved in one incident.
The surge in Taliban attacks appeared to be part of a militant drive to assert their power as NATO forces, led by the U.S., try to build up the Afghanistan military and leave combat responsibility to the local forces by the end of 2014.
Insurgents "poisoned the police" with food at a checkpoint in the Nahri Sarraj district of Helmand province in southern Afghanistan, then attacked the police at the check post late Monday, the governor's office said in a statement.
Four police officers were killed and two were wounded in the attack. The bodies of two civilians also were found at the checkpoint.
The governor's office did not say whether the dead were killed by poisoning or in the fighting.
Taliban spokesman Qari Yousef Ahmadi rejected the government's account of the clashes, saying Taliban fighters attacked the checkpoint and seized weapons and a vehicle but didn't poison the police.
"The way they were fighting, it looked like they might have been on drugs. That's why the police are claiming that we poisoned them," he said. "We didn't."
A government delegation has been sent to the area to investigate.
In neighboring Kandahar province, two Afghan police officers were killed Tuesday morning when their vehicle ran over a roadside bomb in Shah Wali Kot district, provincial police chief Gen. Abdul Razaq said.
In the north, insurgents killed three police officers and abducted 11 in an attack Monday night on a checkpoint in Wardoj district of Badakhshan province.
Provincial spokesman Abdul Marouf Rasekh said the Afghan National Police regained control of the checkpoint on Tuesday.
A search is under way for the 11 police officers who were kidnapped.
Taliban spokesman Zabiullah Mujahid claimed responsibility for the attack.
Also Tuesday, the international military coalition said three NATO service members were killed in the east. One died in a roadside bombing, another in an insurgent attack and a third as a result of a non-battle related injury. No other details were released.
So far this year, 93 NATO service members have been killed in Afghanistan, including at least 52 Americans.
Associated Press writer Mirwais Khan in Kandahar contributed to this report.