Three Chinese nationals were killed and another injured on Tuesday in a suicide attack on the campus of Karachi University in southern Pakistan at the entrance to the school's Confucius Institute, where they worked.

Judging by the yet to be confirmed video available, it looks like a premeditated and planned act of terror with the Chinese nationals as the targets.

The three Chinese nationals killed were teachers at the Confucius Institute. Their Pakistani driver was also killed in the attack, and another Chinese national was injured.

In a bitter irony, the institute, which is dedicated to Chinese language teaching and cultural exchanges, is a symbol of friendship. The Baloch Liberation Army, which seeks autonomy for Balochistan province in the southwest of the country, has claimed responsibility for the blast.

Chinese diplomatic establishments both in Karachi and Beijing have condemned the attack and called for a speedy investigation and severe punishment for the perpetrators. The Chinese Foreign Ministry has expressed "extremely serious concern" and urged the Pakistani government to ensure the safety of Chinese nationals in Pakistan. Pakistani Prime Minister Shahbaz Sharif denounced the attack, and has promised a speedy probe, saying that "the perpetrators will surely be brought to justice".

The Chinese Foreign Ministry also vowed that "those behind this incident will surely pay the price". Tuesday's incident has once again put the spotlight on China-Pakistan cooperation.

As the Pakistani Foreign Ministry said, "The cowardly incident is a direct attack on the Pakistan-China friendship and ongoing cooperation".

Whether, and how well, the Pakistani authorities can provide an effective safety guarantee for Chinese nationals working in the country will greatly affect the many cooperation projects between the two sides, both ongoing and planned ones.

The two neighbors have a longstanding friendship and have collaborated closely over the past decades, particularly on the China-Pakistan Economic Corridor and the Belt and Road Initiative. But terrorist attacks have posed an escalating threat to bilateral cooperation. Chinese interests have recently been clear targets in Balochistan, which is home to multiple cooperative projects.

The Baloch Liberation Army has carried out several terrorist attacks on Chinese nationals in the past. In a July 2021 attack, another suicide bomber blew up a passenger bus and killed 13 people, including nine Chinese nationals working on the construction of a hydropower plant.

For the advancement of China-Pakistan cooperation, the Pakistani government must make greater efforts to guarantee the safety of all Chinese nationals working in the country.

And the latest attack should prompt the two countries to work more closely together on safety concerns and redouble their joint efforts to fight terrorism.