NEW DELHI (AFP) - Indias Twitter-loving junior foreign minister has used the microblogging site to criticise his governments move to tighten rules for long-term tourist visas, his account showed Monday. Shashi Tharoor questioned the logic behind the tougher rules, claiming that the gunmen behind last years Mumbai attacks hijacked a boat and entered the city from Pakistan by sea and had no visas. Issue is not security vs tourism, but whether visa restrictions protect our security. 26/11 killers had no visas, he wrote on Twitter. Under the previous rules, foreigners on five- or 10-year visas were required to leave India every 180 days. Many would simply fly to a neighbouring country for a brief stay before returning. Since November 4, they face the same 180-day deadline, but will have to stay out of the country for two months before they can re-enter. Indian Foreign Ministry spokesman Vishnu Prakash said last week the new guidelines were issued to facilitate bona-fide tourists and that immigration authorities could still allow tourists who leave India to re-enter if they produced a detailed itinerary and ticket bookings. Tharoor said the new visa rules would alienate tourists and cost the economy millions of dollars. But Foreign Minister SM Krishna rebuked the junior minister, saying such sensitive policy matters should not be discussed on the Internet. If there are any (negative) perceptions, then I think they should be sorted out within the four walls of the two ministries, said Krishna, referring to the foreign and home ministries. Tharoor, a former UN undersecretary general, defended himself in Mondays edition of the Hindustan Times newspaper, saying he was only drawing attention to the larger debate on security. Tharoor ignited controversy in September when he joked on Twitter about flying economy class with holy cow politicians in response to new government austerity measures.