Up to 20 militants were killed by security forces in northwestern Pakistan's tribal region on Friday, Xinhua quoted private DAWN NEWS TV channel as reporting. The security forces fired artillery shells at militants' hideouts in Bajaur tribal agency and killed 20 militants, the report said, adding that six security men were killed in three days of clashes in the region. The security forces intensified their offensive against militants in Bajaur Agency on Thursday, killing dozens of militants, according to local newspaper DAWN on Friday. Ground forces backed by helicopter gunships, planes and tanks pounded suspected militant positions in some areas of Bajaur and damaged dozens of hideouts and shops, according to DAWN. Local media reports said that the security forces killed 80 to 100 militants on Thursday. Around 700 militants were killed in the area during the last six weeks, according to DAWN NEWS. Pakistani government earlier declared a ceasefire during the holy month of Ramadan. However, the operations against militants in Swat valley of North West Frontier Province and tribal areas are still continuing.