DATE=8/28/2000 TYPE=CORRESPONDENT REPORT TITLE=IRAN UNREST (S) NUMBER=2-265907 BYLINE=SCOTT BOBB DATELINE=CAIRO CONTENT= VOICED AT: INTRO: An Iranian opposition group based in Iraq has fired mortar shells at a former military base in Tehran. The Iranian News Agency says there were no casualties. Middle East Correspondent Scott Bobb reports the attack follows deadly clashes between conservative hard-liners and reformists in western Iran. TEXT: Mujaheddin Kalq rebels (Monday) said the attack in Tehran was in retaliation for a crackdown by security forces and conservative vigilante groups in Khorramabad. News media in Iran quote sources in the western Iranian city as saying the clashes occurred when thousands of pro-reform demonstrators opposed conservatives trying to break up a conference by Iran's largest student group. They say two pro-reform politicians were prevented from speaking. The Iranian News Agency says a policeman was killed and others wounded Sunday in the unrest. It said calm has since been restored. The closure of virtually all reformist publications and the arrest of a number of journalists have shaken the pro-reform movement in Iran in recent weeks. (SIGNED) NEB/SB/JWH/RAE 28-Aug-2000 08:24 AM EDT (28-Aug-2000 1224 UTC) NNNN Source: Voice of America .