Hong Kong airline Cathay Pacific says passenger traffic slumped last month on plummeting demand from mainland Chinese travellers.

The carrier's September traffic figures released Friday are the latest sign that mainland visitors are staying away from the semiautonomous Chinese city as pro-democracy protests continue.

The company said flight bookings to mainland China on Cathay Pacific and its regional carrier Cathay Dragon tumbled 23.2 % in September from a year ago, contributing to a 7.1 % decline in overall passenger traffic.

The airline did not specifically mention the Hong Kong protests as a factor.

But Cathay said that September, traditionally a strong travel period that leads in to October's National Day holiday, was "another challenging month" with particularly weak demand in the mainland China market for travel to Hong Kong.