HOUSTON, Oct. 14 (Xinhua) -- Firefighters responded to a massive fire at an apartment complex under construction on the outskirts of Houston, Texas early Wednesday morning.

Local media reported that the fire started at around 6:30 a.m. local time (1130 GMT) at an apartment building in the city of Katy, west of Houston. No casualties were reported.

Pictures on social media showed flames continuing to spread at the site as firefighters sprayed water to extinguish the fire.

The cause of the fire is unclear.