Actress Lindsay Lohan and attorneys Mark Heller(R), and Anthony Falangetti sit at a hearing in Los Angeles Superior Court in Los Angeles, California March 18, 2013. REUTERS/Reed Saxon/Pool Lohan enters Betty Ford clinic Lohan leaves rehab: Reports Reid: Lohan 'a mean drunk' Lohan to write rehab blog? Lindsay Lohan grilled by Letterman Lohan a no-show for court date Lohan pregnant tweet a joke Lohan photographed under nightclub table LiLo accuser threatens civil action Lindsay Lohan avoids jail Lohan avoids arrest

Lindsay Lohan has blasted tabloid and Internet reports suggesting she was intent on clubbing on Monday night, hours after she was ordered to serve 90 days in a lockdown rehab, insisting she's taking her troubles seriously this time.

Images of a girl purported to be the embattled actress, crouching down in the back seat of an SUV, outside Hollywood nightclub A/V hit the world wide web on Tuesday morning, but Lohan insists the girl in the vehicle isn't her - and she wasn't in the mood to party after her latest courthouse showdown.

The Mean Girls star took to Twitter.com on Tuesday to defend herself against allegations that she is not taking her punishment seriously enough after accepting a plea agreement to stay out of jail for lying to police officers following a car accident on the Pacific Coast Highway in California last summer.

She wrote, "Guys relax, that was NOT me at A/V or in the... SUV. I'm taking this seriously and focused on the road ahead.

"I stayed in last night, after a pretty long day... and ordered sushi to my hotel... Don't believe EVERY little thing you hear, unless you hear it from me."

And she took the time to thanks fans for sticking by her throughout her troubles, adding, "The support I have gotten, has been great and means alot (sic)."

Reports suggested the girl in the back of the SUV didn't get out of the vehicle when she realised the club was swarming with paparazzi and instructed a friend to drive off.