Nasa has released stunning images of the Sun which show the biggest solar flare of the year.

The huge eruption on April 11th caused a temporary radio blackout on Earth, officials say.

However, they warn the worst is yet to come - with this year expected to see the sun reach its 11 year solar maximum, reports Daily Mail.

The solar flare occurred at 3:16 a.m. EDT (0716 GMT) and registered as a M6.5-class sun storm, a relatively mid-level flare on the scale of solar tempests.

It coincided with an eruption of super-hot solar plasma known as a coronal mass ejection.

'This is the strongest flare seen so far in 2013," NASA spokeswoman Karen Fox explained in a statement.

'Increased numbers of flares are quite common at the moment, since the sun's normal 11-year cycle is ramping up toward solar maximum, which is expected in late 2013.'

Humans have tracked this solar cycle continuously since it was discovered, and it is normal for there to be many flares a day during the sun's peak activity, Nasa said.

Officials dubbed today's solar flare as a 'spring fling' for the sun, which has been relatively calm as it heads into its peak activity period.

The M6.5 flare on the morning of April 11, 2013, was also associated with an Earth-directed coronal mass ejection (CME), another solar phenomenon that can send billions of tons of solar particles into space and can reach Earth one to three days later.

CMEs can affect electronic systems in satellites and on the ground. Experimental NASA research models show that the CME began at 3:36 a.m. EDT on April 11, leaving the sun at over 600 miles per second.

The M-class solar flare was about 10 times weaker than X-class flares, which are the strongest flares the sun can unleash.

M-class solar flares are the weakest solar events that can still trigger space weather effects near Earth, such as communications interruptions or spectacular northern lights displays.

The solar flare triggered a short-lived radio communications blackout on Earth that registered as an R2 event (on a scale of R1 to R5), according to space weather scales.

When aimed directly at Earth, major solar flares and coronal mass ejections can pose a threat to astronauts and satellites in orbit.

They can interfere with GPS navigation and communications satellite signals in space, as well as impair power systems infrastructure on Earth.

Ends/RG/20/04/13