A day after Maharashtra Navnirman Sena(MNS) activists clashed with Samajwadi party workers, attacked two theatres screening Bhojpuri films and assaulted north Indian taxi drivers and vendors, the Centre asked the state Government to tackle the situation in all seriousness and take proper steps to maintain law and order.

After the war of words between Thackeray and Samajwadi MP Jaya Bachchan,who came to the defence of her husband, two motor-cycle borne youths threw glass bottles at Amitabh's 'Prateeksha' residence in Juhu late last night.

Amitabh, who was shooting in Jaipur, refused to comment but security at his two homes in Mumbai was stepped up.

Mumbai was also put on high alert and the situation was peaceful with no fresh incidents of violence being reported.

Samajwadi party general secretary Amar Singh adopted a two-pronged offensive against MNS chief Raj Thackeray. Singh first lodged an FIR against Thackeray in the wee hours accusing him of encouraging attacks on North Indians.

Later, Singh through his lawyer Pradeep Rai petitioned the Election Commission in Delhi demanding that MNS be de-recognised and barred from contesting elections since its leader "does not believe in Indian constitution".