One of the alleged masterminds of an attack by a Pakistani separatist group on the Chinese Consulate in Karachi last month has been killed in Afghanistan along with five associates, the insurgent group that claimed the attack said on Wednesday.

The Baloch Liberation Army (BLA), which opposes projects linked to China's Belt and Road infrastructure initiative in resource-rich Baluchistan, issued a statement on Tuesday confirming the death of Aslam Baloch, one of its leaders.

"The important BLA commander Aslam Baloch, along with five associates in the organisation were martyred in an enemy attack on Monday," Jiand Baloch, a spokesman for the separatist group said in a statement that gave no details.

Pakistan's Samaa Television reported that Aslam was killed along with a number of his commanders in a suicide attack in Aino Maina in Kandahar province.

A spokesman for the Pakistani foreign ministry did not respond.

Last month, three attackers stormed the Chinese Consulate in Karachi, killing four people. Security forces killed the three attackers who were carrying explosives.

Pakistan has long accused its old rival India of supporting insurgents in Baluchistan. India denies helping Baluchistan insurgents and accuses Pakistan of nurturing Islamist militants throughout the region.

China has funded development of a deepwater port at Gwadar in south Baluchistan, and is also investing in other projects as part of the giant China Pakistan Economic Corridor (CPEC).

Baluchistan, on the borders of Afghanistan and Iran, has rich mineral and natural gas reserves but is Pakistan's poorest province.

Separatists have for decades campaigned against what they see as the unfair exploitation of resources, in particular natural gas and minerals.