An official who was mayor of a northern Chinese city when a massive chemical explosion killed at least 165 people is under investigation for bribery, the country’s top prosecuting authority said Sunday.

Huang Xingguo, 62, headed the response committee after the explosion rocked Tianjin in August 2015, devastating a huge swathe of the port city.

He was also acting party chief of the municipality at the time.

In a brief statement posted Sunday by the Supreme People’s Procuratorate, the country’s top prosecuting office, it said it was investigating Huang “on suspicion of taking bribes” and had taken “coercive measures”.

Such measures may include residential surveillance, summons by force, and detention, according to the official Xinhua news agency.

The statement did not mention the Tianjin disaster, China’s highest-profile industrial accident in years.

In November Chinese courts jailed almost 50 company managers and government officials over the deadly blasts for charges ranging from illegal storage of materials to abuse of power.

A government report found that officials had routinely ignored or violated laws and regulations on chemical storage.

Fears of toxic pollution were rife following the explosion, with cyanide levels in the disaster zone far above national limits.