Oil dropped to the lowest level in four months on Monday as turbulence in Chinese equity markets raised concern about economic growth in the world’s top importer of crude and refined products.

With the market also struggling against a persistent supply glut, Brent crude — the international oil marker — hit its lowest since March, shedding $1.29 to $53.33 a barrel. West Texas Intermediate — the US benchmark — fell 94 cents to $47.20, a level last hit in early April.

The price of Brent rebounded in May to $69.63 a barrel after dropping to a near six-year low of $45 a barrel in January. Although some traders had bet depressed oil prices would crimp supply and ease the glut that set the price rout in motion a year ago, supplies are still far outstripping demand.