A medical helicopter crashed in a mountainous area near Porto, Portugal's second biggest city, with all four onboard feared dead, local media and the country's INEM emergency service reported on Saturday.

State broadcaster RTP and daily Correio de Manha reported the helicopter had crashed, killing two pilots, a nurse and a doctor onboard. INEM said a rescue operation was under way but the helicopter had still not been found.

The INEM helicopter went missing at around 6.30pm on Saturday after dropping off a 76-year-old patient suffering from cardiac problems at a hospital in Porto.

A spokesperson at the Valongo fire station in the region said 200 recue workers were searching for the helicopter.

According to INEM, the helicopter was on its way back to its base in the district of Braganca when it crashed in bad weather.

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.