An NHS ambulance trust will remain in special measures despite showing improvements in care, a health watchdog has said.
South East Coast Ambulance Service NHS Foundation Trust (Secamb) was visited by the Care Quality Commission (CQC) between July and September.
Inspectors said although some areas had improved, it was "too early" to judge if the improvements were sustainable.
Secamb said it was "aware there remains work to be done".
The trust, which covers Kent, Sussex, Surrey and North East Hampshire, was previously rated inadequate following inspections in 2016 and 2017.
The rating has now been upgraded to requires improvement.
A CQC spokesman said inspectors found although staff were well-motivated, there were staff shortages which had an impact on both worker and patient safety.
He said: "On emergency calls, the trust was above the national average for category 1 and 2 response times, for people with life-threatening injuries.
"However, some patients classified as category 3 or 4 were at an increased risk as a result of experiencing long delays."
Daren Mochrie, Secamb chief executive, said he was confident the trust was "on the right path".
In a statement he said: "We are aware there remains work to be done and this has already been taking place since the inspection.
"I know that right across the trust, staff are committed to further improve the services we provide to our patients."
The chief inspector of hospitals, Professor Ted Baker, said he was pleased to see "signs of change" but recommended the trust should remain in special measures in light of the report.
He said: "Although there has been progress in addressing the immediate issues, we felt it is still too early to judge their effectiveness."