Militants have killed 18 police officers including a senior official in an ambush in southern Afghanistan, the interior ministry says.
Fighting continued all day after the attack on Monday afternoon on a dirt road in Helmand province, in which four officers were also injured.
Some 150 police officers were said to be travelling in the convoy which was attacked by dozens of militants.
Taleban elements have been blamed for previous attacks in the region.
Those killed included a senior police official in Helmand, Amanullah Khan, a spokesman for the interior ministry told news agencies.
He had been on his way to present a new district police chief when the ambush happened.
The spokesman, Yusuf Stanizai, blamed the attack on "enemies of peace" - a term Afghan officials often use to mean militants loyal to the ousted Taleban government.
He gave no indication of militant casualties but said the fighting had continued until 0100 on Tuesday (2100 GMT Monday).
Another official at the interior ministry, Dad Mohammed Rasa, was quoted by the Associated Press news agency as saying the ambush had been "the deadliest ever on the police".