Twenty-six hospitalised as heatwave blasts Sydney Marathon runners

Some 17,000 people have taken to the streets for the annual Sydney Marathon amid a stifling spring heatwave.

While thousands finished the harbourside event, a NSW ambulance spokesperson said by 4pm 26 people had been hospitalised and another 14 treated by paramedics at the scene.

Seven of those in hospital were in a serious condition after the temperature hit 30 degrees on Sunday.

READ MORE: Incredible temperatures forecast for Australia in dramatic heat shift

The race began at Bradfield Park at Milsons Point with runners crossing the Sydney Harbour Bridge and continuing through the Sydney CBD, Pyrmont, The Rocks, Darlinghurst, Moore Park, and Centennial Park.

Morocco's Othmane El Goumri won the men's marathon and Betsy Saina, from Kenya, was the fastest woman across the line.

Brett Robinson was Australia's top placed male contender, crossing the finish line in 8th overall.

Madison de Rozario was the female winner of the wheelchair Marathon.

In a later instagram post she called her win a "great day in office and I will take it with all my heart."

El Goumri dedicated his win in the Sydney Marathon to victims of the recent earthquake in his country, racing in honour of his loved ones affected by the tragedy.

This year there were more road closures than normal because the event is an Abbott World Marathon Majors candidate event.

A high-visibility police operation was underway throughout the day, with people coming into the city urged to plan their trip around the closures and expected delays.

"There will be a number of major road closures in the CBD and surrounding suburbs in order to facilitate this world-class event," Acting Superintendent Samuel Nelson said.

"However, we will also work to minimise the impact of the event on road users, local residents and the wider community."

Crowdsrow in the CBD with a planned and authorised march on Cleveland Street at 2.30pm.

"We are working with Transport for NSW to monitor the two events and we urge motorists to be mindful of even further extended delays," Nelson said.

"If you must travel into the Sydney CBD, leave the car at home and utilise public transport."

Those who do travel by car are urged to check and double-check parking signage, as special event clearways will be in place between 1am and 1.30pm in the Sydney CBD, North Sydney, Pyrmont, Darlinghurst and Moore Park.

Cars – even those with parking permits – left in those clearways will be towed.

Major closures to be in place

"The Sydney Harbour Bridge, Cahill Expressway and Western Distributor will close from 4am to 10am," Transport for NSW Coordinator General Howard Collins said.

"The Sydney Harbour Tunnel will remain open but extensive delays are expected.

"Major roads from the Sydney Opera House to Moore Park, including Macquarie St, College St, Park St, and parts of Oxford St and Flinders St will close between 4am and 3pm."

Sydneysiders were warned of road and transport chaos today with significant bus detours with different stops and early ends to trips.

READ MORE: Huge changes looming for new iPhone model

Collins urged everybody, especially motorists, to avoid non-essential travel around Sydney on Sunday.

"If you must drive, be aware that significant detours will be in place and long delays are expected – so, please leave plenty of extra time to reach your destination, particularly when driving between the Sydney CBD and eastern suburbs," Collins said.

"Motorists will only be able to travel east/west across the course via Cleveland St or the Cross City Tunnel, which will be toll-free from 5am to 3pm on the day, however, lengthy delays are still expected."

READ MORE: Ukraine warned its offensive could have only 30 days left

Here is the full list of the times and road closures on Sunday.

• 3.30am to 11am: Roads at the start line in Milsons Point including Alfred St South.
• 4am to 8.30am: Roads in Millers Point and Barangaroo including sections of Watsons Rd, Upper Fort St and Argyle St.
• 4am to 9:30am: Roads in Pyrmont north including Bowman St and Pirrama Rd.
• 4am to 10am: Sydney Harbour Bridge, Cahill Expressway, Western Distributor and some roads in Milsons Point and Pyrmont.
• 4am to 10:30am: Roads in Millers Point including Hickson Rd, Dalgety Rd and Towns Place.
• 4am to 11am: Roads in The Rocks and Dawes Point including Hickson Rd and George St.
• 4am to 2pm: Roads in Moore Park including Moore Park Rd, Driver Ave. Centennial Park will also be closed to vehicles. Eastern Distributor Bondi Exit to Moore Park Rd will close from 2am – 4am and from 1:15pm – 2pm.
• 4am to 2:30pm: Park St, College St, Oxford St and Flinders St from the city, Darlinghurst through to Moore Park.
• 4am to 3pm: Roads in Sydney CBD east including Macquarie St, Bridge St, College St and Art Gallery Rd.
• 5:30am to 11am: Roads in Sydney CBD north and Circular Quay including Bridge St, Pitt St, Loftus St and Young St.
• 6:30am to 12pm: Southbound lanes of Anzac Pde from Moore Park Rd to Lang Rd at Moore Park. Eastern Distributor Randwick Anzac Pde exit will also be closed.