BP activity loop used in custom code

This code is used in a custom plugin (outside of BuddyPress) to retrieve activity stream:

function mn_student_activity($student) {

if ( bp_has_activities( bp_ajax_querystring( 'activity' ) ) ) {
while ( bp_activities() ) {
bp_the_activity();
locate_template( array( 'activity/entry.php' ), true, false );
}
}
}

It didn't work initially but changing "locate_template" to load_template() function helped. However, it doesn't work as expected: it loads only a single activity with broken CSS. How do I fix this or what did I missed here?