Bangladesh was bracing for a more unrest after riot police clashed with thousands of protesters demanding electoral reforms and postponement of January 22 elections, police and news media said. Police used batons, tear gas and rubber bullets on stick-wielding, stone-throwing demonstrators Sunday in the capital, Dhaka, the ATN Bangla television station reported. Several protesters and police were hurt. Schools and businesses were closed and transport was disrupted nationwide as a three-day transport blockade, imposed by a 19-party alliance, started Sunday. The alliance, led by former prime minister Sheikh Hasina, said it plans to keep blocking roads, railways and river routes Monday and Tuesday to isolate Dhaka from the rest of the country in an effort to force its demands. But the country's interim leader, President Iajuddin Ahmed, said he could not change the constitutionally mandated election date. About 12,000 security forces patrolled Dhaka's streets amid fears of a repeat of the violence that has marred previous political protests, and has left at least 34 dead since October. About a dozen protesters were seriously injured in one area Sunday when police charged with batons, witness Ruhin Hossain said by phone from the scene. Nearby, police fired rubber bullets and tear gas at protesters near the home of an Awami League leader, said police official Kankan, who uses a single name. Kankan said that at least four police were wounded. Under the constitution, the interim government has only 90 days to hold the elections. Ahmed took over as interim leader on October 29 and his 90-day term expires on January 25.