DHAKA, Aug 15 (Reuters) - Police and activists fought running battles and at least 50 people were injured on Thursday during a half-day strike in Bangladesh called to demand the execution of the killers of the country's independence leader.

Sheikh Mujibur Rahman launched Bangladesh's independence struggle against Pakistan in 1971. Mujib and most of his family were killed in an army coup on August 15, 1975.

As the strike ended at midday, traffic poured back on the roads, stock exchanges resumed trading and shops were reopened, witnesses said.

Activists from Mujib's Awami League, Bangladesh's main opposition party, threw stones at police as they fired teargas shells and used batons to try to disperse the demonstrators, one witness said.

"It was one hell of a battle going on," he told Reuters, adding that at least eight people were rushed to hospital.

Some reporters on the scene put the number of injured between 50 and 100, and police said some of their constables were also injured and needed treatment.

Former Awami minister Saber Hossain Chowdhury said police detained about 200 activists during the strike, which he said could be the beginning of a lengthy anti-government protest.

"They (government) are hitting us everywhere, laying false charges against our leaders and arresting our people," Chowdhury told Reuters.

"We will review the situation and give an appropriate response," he said without explaining.

The Awami League called Thursday's strike to press for the immediate execution of Mujib's convicted killers. The league is headed by one of Mujib's daughters, former prime minister Sheikh Hasina.

Hasina and her sister Sheikh Rehana survived the 1975 coup because they were abroad at the time.

Awami says it is dismayed over the long delay in executing 12 former army officers who had been sentenced to death by the country's highest court in April last year for killing Mujib.

Only four of the convicts are in custody. The others have absconded, police said.

Awami supporters are also protesting against a government decision to cancel an August 15 public holiday Sheikh Hasina introduced when she was prime minister.

Her rival, Prime Minister Begum Khaleda Zia, believes her husband, former president General Ziaur Rahman, is the country's independence leader instead of Mujib, and cancelled the holiday after she won elections last October.

Awami leaders said Hasina would announce further protests at a Dhaka rally on Sunday.

Bangladesh has a history of political disputes and violence that have damaged the nation's economy and curbed foreign investment because of frequent strikes, analysts say.

Nearly half of Bangladesh's 130 million people still live in poverty, and business leaders often blame politicians for neglecting their interests. Nampa-Reuters 1102 150802 WEB story ENDS (NAMPA 151106)