A Filipino patrol boat searching for three Indon tugboat crew members kidnapped by pirates near the southern Philippines clashed with gunmen near Sibutu island, killing two of them, officials said. Philippine Navy regional commander Commodore Rufino Lopez said his men ordered two suspicious speedboats to stop for inspection, but its passengers opened fire on the patrol boat triggering a sea chase in the Celebes sea on Saturday afternoon.The battle left two gunmen dead, but the others managed to escape on the second speedboat, Lopez said. "Two gunmen are dead and we have recovered their boat," he told the Arab News. It was unknown if the gunmen were part of a group that kidnapped on March 30 the crew of the Malaysian tugboat Bongagaya 91. The pirates hijacked the tugboat off Sabah, herded the trio and fled towards the scattered islands where Abu Sayyaf militants are known to actively operate.