Authorities imposed restrictions in and around Srinagar city's centre Lal Chowk on Saturday to prevent separatist called protests.All pedestrian and vehicular movement was prevented in and around Lal Chowk to thwart separatist called protests on the 27th anniversary of Gaw Kadal massacre in which over 60 protesters were killed by security forces in 1990.Coils of razor fitted concertina wire were placed on the road to obstruct traffic as paramilitary and state police contingents in full riot gear manned the city.Police on Friday arrested separatist leader Yasin Malik from his uptown Maisuma residence, to prevent his participation in Saturday's protest.