Fire broke out on Kilvey Hill on Thursday evening, sending flames up the hillside above St Thomas and a plume of smoke drifting across Swansea.
South Wales Police and Mid and West Wales Fire and Rescue Service confirmed they were aware of the fire, with people in the vicinity told to keep windows and doors closed because of the smoke.
Swansea Council leader Rob Stewart urged residents to avoid the area and follow the advice of the emergency services.
Images shared by Cllr Stewart show flames breaking through the gorse close above rooftops, with smoke towering over the hill and drifting across the east of the city.

The fire burned close to homes around Grenfell Park Road, near a school, with residents across the east of the city reporting smoke and falling ash through the evening.
Locals say firefighters had the blaze under control by around 11pm — at times letting it burn in a controlled way — and that nobody was evacuated, though some residents of Wallace Road chose to leave their homes for a time before returning.

By late on Friday morning the hillside was still smoking, according to residents. The full scale of the damage is not yet clear, and the cause is not known.
It is the third fire on the hill in fifteen months. In April last year, a blaze spread across 12 hectares of the hillside, with crews still damping down the following day.
Last July, firefighters tackled two separate seats of fire on the hill, one measuring roughly 200 metres by 200 metres, using knapsack sprayers, blowers and beaters through the evening.
The hill has seen worse still: in 2019, six homes on Deep Glade Close in St Thomas were evacuated just before midnight as flames threatened houses, with more than 45 firefighters tackling what one evacuated resident was told was a “touch and go” situation.
Kilvey Hill is one of Swansea’s best-loved green spaces — a community woodland and wildlife refuge ringed by homes in St Thomas, Port Tennant, Dan-y-graig, Bonymaen and Pentrechwyth.
The hill is also a construction site. The £49m Skyline gondola and luge attraction began building in May, and tree felling along the gondola corridor above St Thomas is due to continue through the summer.
There is no suggestion the works are connected to the fire.
The blaze comes at the end of a week in which crews have fought wildfires across Wales after a long dry spell, with the Welsh Government activating its crisis management arrangements in response.
The largest, at Blaenavon, has burned for days and sent smoke over communities miles away.
Grass fires in dry conditions can spread with frightening speed — anyone who spots one is urged to call 999 immediately and not attempt to tackle it themselves.
The smoke plumes that towered over the hill on Thursday evening had gone by Friday morning, leaving the hillside smouldering, a day before the Wales Airshow brings crowds and aerial displays to Swansea Bay.
Related stories from Swansea Bay News
Firefighters continue to dampen down 12 hectare Kilvey Hill fire
The April blaze that spread across 12 hectares of the hillside.
Fire crews tackle Kilvey Hill blaze as wildfire risks persist
Two seats of fire on the hill last July, and the pattern behind them.
KILVEY HILL: Tree felling to continue ‘for months’ as Skyline gondola corridor takes shape
Where the £49m gondola project has got to on the hill.
