Hong Kong shares closed at their lowest level in more than five weeks on Wednesday, dragged down by energy and utility stocks as investors fretted over Syria and most regional markets slid again.

Shares in mainland energy giant PetroChina dived 4.4 per cent while its subsidiary Kunlun Energy plunged 13.5 per cent after reports that key executives were under investigation for “severe breaches of discipline”.

The Hang Seng Index ended down 1.6 per cent at 21,524.65, its lowest closing since July 22. The China Enterprises Index of the top Chinese listings in Hong Kong fell 2.2 per cent to its lowest since August 9.