Cathay Pacific Airways has cancelled two flights connecting with the Pakistani city of Karachi, whose airport - the country's busiest - came under a Taliban raid this week.
The carrier was closely monitoring the developments to see if more cancellations were needed, a spokeswoman said.
"In view of the situation at Jinnah International Airport in Karachi, Cathay Pacific is reviewing and assessing the safety status of the airport," the airline says.
The affected flights were CX703 from Bangkok to Karachi yesterday, and CX2700 from Karachi to Bangkok today.
Cathay operates four flights a week between Hong Kong and Karachi. All these flights operate via Bangkok.
The airline's shares closed down 0.14 per cent at HK$14.48 on the Hong Kong stock exchange yesterday.
Cathay's move came after the Security Bureau issued a red travel alert for Pakistan, which means there is "significant threat" to those visiting the country and that Hongkongers should avoid non-essential travel.
A red signal is in the middle of the government's three-tier travel alert system, in which a black signal means "severe threat" and an amber signal implies "signs of threat".
International flights in and out of Karachi have been suspended twice since Sunday, when gunmen wearing military uniforms stormed the airport, firing rocket-propelled grenades in an all-night siege that killed 34 people.
In Islamabad, Pakistani Prime Minister Nawaz Sharif chaired a meeting with security officials late on Tuesday to discuss how to handle the crisis as the escalation of violence raised the prospects of an all-out army campaign against insurgent strongholds.
The Pakistani Taliban, a loose alliance of insurgent groups united by anti-state jihadist ideology, said it had carried out the Karachi attack in response to strikes on its positions on the Afghan border.