Syrian forces battled a group of Islamic extremists holed up in a farmhouse in Idlib, 330 kilometers (200 miles) north of Damascus on Thursday, killing eight in a fight that ended when some of the gunmen blew themselves up rather than be captured, state-run Syrian Arab News Agency said. The gunbattle was the second clash with insurgents this week. Syria also announced Wednesday it had uncovered a bomb-making factory in the northern city of Aleppo, with manuals for attacks on public buildings and security headquarters in Syria. The sweeps against militants come as Damascus is under intensifying US pressure to stop Islamic extremists from entering Iraq to join the insurgency against US and Iraqi forces. It is not known, however, whether the crackdown is in part a response to the pressure. Syria has suggested the militants have links to Iraq, but has been unclear whether they were intending to cross into Iraq or to carry out attacks in Syria.