ISLAMABAD, July 9 (Xinhua) -- Chinese Ambassador to Pakistan Luo Zhaohui has condemned the violent incident in which four Chinese citizens were attacked Sunday evening in northwestern Pakistan.

In a press release by the Chinese embassy here early Monday, Luo requested the Pakistani side "to investigate it, round up the culprits, properly handle the follow-up issues and take effective measures to protect all the Chinese in Pakistan."

Four Chinese citizens were attacked by unidentified gunmen at Peshawar, the capital city of Pakistan's North West Frontier Province with three of them killed and the fourth seriously injured, according to the Chinese embassy.

Mao Siwei, deputy chief of the Chinese embassy in Pakistan, has left for Peshawar with a few Chinese diplomats to deal with the issue, it said.

Earlier, Pakistani Foreign Office spokesperson Tasnim Aslam Sunday night said that Pakistan condemned the killing of Chinese citizens in the country.

She added that the incident would not affect Sino-Pak friendship.