At least six people have died from heat-related causes this year in metropolitan Phoenix, capital of the US Southwestern state of Arizona, as temperatures soared to 46C (115F) this week, local officials reported.

In addition to the confirmed deaths, another 87 fatalities are under investigation for potential heat-related causes, the Maricopa County Department of Public Health said in its latest weekly update.

Phoenix saw its hottest days so far this year on Thursday and Friday, hitting 146C (115F). The metro area remains under an excessive heat warning due to a high-pressure system, although some moisture and a slight cooling are anticipated over the weekend.

A heat wave is currently afflicting much of the US, with many regions facing record-breaking temperatures.

The heat wave, arriving early in the summer, comes as another warning sign that the effects of global warming are being felt sooner rather than later, and that urgent action is needed to fight it. (Anadolu Agency: Text, Excluding Headline)