A Chinese supervisor at a dam construction project in Pakistan is under police protection after workers accused him of blasphemy, officials said Monday.

Police moved in as crowds gathered at the Dasu hydropower project in Kohistan district on Sunday afternoon and officers took the man to a safer location, police official Naseer-ud-Din Khan said.

Officials said the engineer at the Dasu hydropower project in northwestern Khyber Pakhtunkhwa province was accused of blasphemy after he highlighted the "slow pace of work" during the holy month of Ramadan.

"The laborers said they were fasting but denied that work had slowed down, which led to an exchange of heated words" with the supervisor, a police official said on condition of anonymity.

"Later, the laborers accused the engineer of making blasphemous remarks" and around 400 locals gathered to protest, he said.

Hundreds gathered again on Monday morning and stormed the main district police station, believing the man was hiding in the building, Khan added.

But officials, fearing the man might be attacked, had moved him to another district by military helicopter, Khan said.

The man was charged and had so far declined to give a statement, police officials said.

A local administration official in Dasu, around 180 kilometers north of the capital Islamabad, said the army and paramilitary troops were deployed "to ensure the safety of the engineers."

The Dasu Dam construction contract was awarded to the China Gezhouba Group Company in 2017, and the project is shrouded by tight security.

Khan said the crowd attacked the police station as officers were preparing the prosecution paperwork on Monday.

"The mob dispersed only after they were shown a copy of the case registered on blasphemy charges," he said.