KABUL, Afghanistan — Afghanistan’s police force took another severe blow from the Taliban on Saturday, as 17 police officers were killed in a clash with the insurgents in the southern province of Helmand, officials said.

The insurgents overran a police base near the center of the strategically important district of Musa Qala, the officials said. Local police officers and witnesses described a large-scale attack that began after midnight and continued until daylight.

“There are also casualties to the Taliban, but we do not know the figures,” said Omar Zwak, the spokesman for the governor of Helmand Province. “We are investigating how this happened. Why didn’t the district center headquarters send reinforcements? It’s a big loss. We are saddened.”

Of the 19 police officers stationed at the base, 17 were killed and two were wounded, he said.

One police officer, stationed at a base near the one that came under attack, said the insurgents surrounded it and by dawn had completely destroyed it. Roads around the base, known as the Takhtapol base, were planted with mines and booby traps, preventing its defenders from escaping and other officers from coming to their aid, the officer stationed at the nearby base said.