The incident, which took place Tuesday morning in the coastal province of Huaral, damaged at least four houses near the tunnel and forced the company to suspend construction.

The prosecutor's office said on its Twitter account that it has started a preliminary investigation into individuals at the company that it said may bear responsibility.

COSCO Shipping Ports did not immediately respond to a Reuters request for comment.

As part of the project, COSCO is building a 1.1 mile (1.8 km) tunnel under a residential neighborhood in the city of Chancay to connect the port with a highway. The $1.3 billion project's first stage is set to be completed by the end of next year.

The prosecutor's office also said it has asked the company to report on works it has been carrying out "under the penalty of being denounced for disobedience to authority."

The port is envisioned as a hub for Peru's Pacific coast to facilitate more trade with Asia.

(Reporting by Marco Aquino; Writing by Carolina Pulice; Editing by Christopher Cushing)