ISLAMABAD -- Two Chinese nationals were killed, one Chinese national injured, and several Pakistani nationals were killed and injured in a terrorist attack in Pakistan's southern port city of Karachi on Sunday night, the Chinese embassy in Pakistan confirmed.

The attack happened at about 11:00 p.m. local time on Sunday (1800 GMT) when a convoy from the Port Qasim Electric Power Company was attacked by terrorists near Jinnah International Airport in Karachi, the capital city of the country's south Sindh province, the embassy said in a statement.

"The Chinese Embassy and Consulate in Pakistan strongly condemn this terrorist act, express deep condolences to the victims of the two countries, and extend sincere condolences to the injured and their relatives," the statement said, adding that the Chinese side has been working with the Pakistani side to do their best to deal with the aftermath of the incident.

A big fire following a huge blast on Sunday night engulfed several vehicles near an airport in Karachi, police said.

The Chinese missions in Pakistan have initiated emergency response work as soon as possible, requiring Pakistan to do its best to treat the injured, conduct a thorough investigation of the attack, and severely punish the perpetrators, the statement said.

The embassy stressed that practical and effective measures to ensure the safety of Chinese citizens, institutions, and projects in Pakistan should be taken by the Pakistani side at the same time.

"The Chinese embassy and consulates in Pakistan remind Chinese citizens and companies in Pakistan to be vigilant, pay close attention to the local security situation, strengthen security measures, and make every effort to take safety precautions," said the statement.

The banned outfit Balochistan Liberation Army (BLA) has claimed responsibility for the attack through a statement on a social media platform, while the Pakistani authorities have not confirmed it.