MULTAN, Pakistan (AP) — Police in Pakistan say they have detained eight Chinese nationals who tried to enter a power plant with weapons in the eastern Punjab province.

Officer Zafar Iqbal says the eight men were stopped at a checkpoint on Sunday outside the Qadirabad power plant in Sahiwal after a pump-action gun, a handgun, a rifle and ammunition were found in their vehicle. He says an investigation is underway.

China has heavily invested in energy and other projects across Pakistan as part of its global “Belt and Road” initiative, and has sent thousands of workers to the country.

A suicide bomber struck a bus carrying Chinese engineers in the Baluchistan province on Saturday, wounding three of them as well as three paramilitary guards. The Baluch Liberation Army, a separatist group, claimed responsibility.