Government supporters and foes fought with bombs, iron rods and sticks in Dhaka and at least 13 other cities during a daylong strike Tuesday and at least 260 people were injured, witnesses and news reports said. Two big opposition parties, the Awami League and the Bangladesh Nationalist Party called the strike to force President Hussain Muhammad Ershad to resign. A senior police official said several people were detained for rioting, but he refused to give a number or to allow his name to be used. Police burst tear gas shells and repeatedly fired in the air to disperse protesters throughout Dhaka, the capital city of 7 million people, witnesses said. At least 60 people were injured in political frays, including five who suffered bullet wounds, they said. The strike was the seventh opposition-sponsored shutdown the past month. It closed businesses and halted traffic in Dhaka and several other cities, the opposition claimed. Government offices were open, but few people went to them. At least 40 people were injured in political fighting in the port of Chittagong and at least 100 in Rajshahi, 120 miles northwest of Dhaka,, the United News of Bangladesh news agency said. The Bengali-language daily Sangbad said an additional 60 people were injured in clashes in 11 other towns. Abdus Salam Talkdar, secretary-general of the opposition Bangladesh Nationalist Party, told reporters three people raided the house of party president Khaleda Zia on Tuesday. He said Mrs. Zia was not at home, but the attackers assaulted her son and two servants. He said one raider demanded to know where she was and said repeatedly: ``I will kill her.'' Ershad, a 60-year old former army general, seized power in a bloodless coup eight years ago. He has promised elections next year, but the opposition has sworn to boycott all elections under Ershad. They say he must first step down and appoint a caretaker government. Ershad left for the Maldives on Tuesday for a summit of the South Asian Association for Regional Cooperation.