DHAKA (AFP) - Bangladeshi police fired teargas at scores of protesters on Sunday as violence broke out during a day-long opposition strike in the capital Dhaka. The main opposition Bangladesh Nationalist Party (BNP) and its Islamist allies enforced the strike in protest at the governments decision to divide the 400-year-old city into two administrative zones. Protesters became unruly as they pelted bricks and stones at police and torched a police van and motorcycle. We fired teargas to prevent vandalism, deputy commissioner of Dhaka police Khorshed Alam told AFP. The mayor, a senior BNP official who will lose his job in changes to how the city is run, was hauled into a police van at the protest but later released. Schools and businesses were closed and roads largely deserted as the strike took effect. Several BNP activists were hurt in scuffles with police at a dawn rally. The government recently ratified a new law splitting Dhaka into two administrative zones, which it said would improve services and utilities for the citys 15 million people. The opposition criticised the move, saying it was politically motivated as the new system forced the citys elected mayor out of office. Police spokesmen said at least 13,000 law-enforcers including about 3,500 members of the elite Rapid Action Battalion were patrolling the roads and flashpoints in the city.