Armed attackers attempted to storm the Chinese consulate in the Pakistani city of Karachi on Friday morning local time, killing four people, authorities said.

Three attackers were also killed in the assault on the consulate in the city's high-security red zone, according to a Pakistan foreign ministry spokesman.

The Baloch Liberation Army, a separatist group, claimed responsibility for the attack in a tweet including a photo of three unidentified men and the message: “Karachi: Fidayeen of BLA attacked the Chinese embassy in Karachi.”

“Fidayeen” is an Arabic term that loosely translates as “one who sacrifices himself.”

In a statement released after the attack, the group said its objectives were “clear — we will not tolerate any Chinese military expansionist endeavours on Baloch soil.”

CNN does not have independent confirmation of the group's involvement.

Security was immediately ramped up at consulates all over Karachi, Sindh Governor Imran Ismael told CNN.

Two of the four victims were uniformed police officers, according to Seemi Jamali, the Head of Emergency at Jinnah Hospital. No Chinese nationals were among the dead, the hospital said.

Pakistan's Prime Minister Imran Khan condemned the attack, ordering a “complete inquiry.”

In a statement, Khan called it “part of conspiracy against Pakistan and China's economic and strategic cooperation.

When journalist Amir Latif, from Turkey's Anadolu News Agency, spoke to CNN he could still hear gunshots.

“(The consulate is in) a very heavily guarded area, the firing is still continuing and we can hear small blasts, which suggests the attackers are still engaged with security forces,” Latif said.

It's unclear whether the terrorists were inside the compound or near the consulate.

Pakistani Foreign Minister Shah Mehmood Qureshi later confirmed that the operation to secure the Chinese compound was over.

“Pakistan and China's friendship cannot be disturbed. Pakistan and China have joint security attempts to prevent such attempts at destroying the work that the two countries are working on.”

The Balochistan Liberation Army (BLA) has conducted a low-level separatist insurgency against the state for nearly two decades.

The organization, which grew out of anger over the state's perceived monopoly of the province's mineral resources, previously have killed and kidnapped Chinese engineers working in the province.

Balochistan is at the core of the massive multi-billion dollar cooperation deal known as China-Pakistan Economic Corridor (CPEC).

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