Jamiroquai frontman Jay Kay has said he is "distraught" at having to postpone the band's two forthcoming Greenwich shows due to complications with his back.

They were due to perform at the O2 Arena on June 23 and 24, but due to the singer's rehabilitation following a recent operation the shows have been moved to December 3 and 6.

Kay, 47, said he is feeling "very low" at having to delay the concerts and his "inability to perform properly".

In a statement on the band's official Facebook page, he said: "It is with great regret that again I have to disappoint people due to the ongoing problem with my back.

"I have never felt so frustrated with a situation as I feel now, and I am desperate to get back to form.

"After two operations I am only marginally more active, and I know I could never give the 125% energy I need to give to you good people a super show."

He said he is a "proud man" and is "asking for people's patience".

"I am distraught at this and am feeling very low."

Referring to the recent deaths of friends including the band's original keyboardist, Toby Smith, Kay said: "2017 is turning out to be a tough year, with the loss of several close friends in quick succession and the inability to perform properly in the way I've been doing, and the only way I know how to, since I did my first gig at 17 years old.

"I want to thank all of you for the messages of support you have sent me. I can't quite believe how kind you all are. A thousand thanks."

The singer apologised to fans who had made plans to travel to the band's shows in Paris, Athens and London, and promised he would return to perform the shows as the fans "deserve".

He signed off his message "from a very wounded Buffalo".

A statement from the acid-jazz band's team confirmed that all tickets for the June shows will be valid for the rescheduled dates, but refunds are also available from the point of purchase.

The statement said: "Jay Kay is currently recuperating and in rehabilitation after his procedure last week and as a result has been advised to postpone the two shows later this month at the O2 Arena, London, which will now take place on Sunday the 3rd and Wednesday the 6th of December 2017.

"Please note that tickets for the postponed O2 show on Friday 23rd June will only be valid for the rescheduled show on Sunday 3rd December. Tickets for the O2 show on Saturday 24th June will only be valid for Wednesday 6th December."

MORE: Jamiroquai star posts from hospital bed after 'stunningly painful' surgery

In May, Kay told his fans in a post on Instagram that he had undergone a "stunningly painful" surgical procedure on his back, involving injections into his spinal discs.

Jamiroquai, known for tracks including Virtual Reality, Space Cowboy and Cosmic Girl, recently released their eighth album, Automaton.