DHAKA, Aug 21 (Reuters) Classes and exams were postponed in Bangladesh's biggest university today after about 100 students were injured overnight in a campus battle with security forces, officials and witnesses said.

The violence erupted yesterday evening after the students protested against the presence of army troops at a stadium at Dhaka University during a football match, they said.

The troops assaulted some protesters, fuelling the unrest that soon spread across the 40,000-student campus. Hundreds of police rushed in, fired teargas and rubber bullets, the witnesses said. The students hit back with sticks and stones.

The battle raged through most of the night before the students returned to their dormitories. University authorities postponed all classes and exams.

The students have called for an indefinite strike at the university.

Troops have been camping at the gymnasium since the country's army-backed interim government imposed a state of emergency in January, in the wake of widespread political violence.

It banned all political activities and protests.

Yesteray's unrest was the first major defiance of the emergency restrictions, officials said.

The students demanded immediate dismantling of the army camp on the campus, which remained tense today, though there was no fresh violence.

The chief of army general staff, Major-General Sina Ibn Jamali, visited the Dhaka Medical College Hospital to see the injured and said the offenders would be punished.

REUTERS SV PM1128