At least three policemen were killed and four others injured early Wednesday morning when a group of militants attacked a police station in Dera Ismail Khan, a town in Pakistan\'s northwest province of Khyber Pakhtunkhwa, reported local media Duniya.According to the report, an estimated 14 militants were involved in the attack. Details about the attack are not immediately available.The report about the attack by militants on a police station in Dera Ismail Khan came just one day after a widely reported ceasefire announced by Pakistani Taliban in the country.Late on Tuesday, local media quoted a foreign media report as saying that Pakistani Taliban (TTP) had declared a nation-wide ceasefire in support of the peace talks with the Pakistani government and the ceasefire had actually been in effect since October.However, a lot of clashes between the militants and the security forces have been reported in Pakistan\'s northwest and southwest regions over the last week or so. Both Pakistani government and army have denied any talks with Pakistani Taliban. Even the Pakistani Taliban spokesman Ihsanullah Ihsan also denied the talks while talking to reporters in Peshawar on telephone on Tuesday.Wednesday morning\'s attack on a police station in Dera Ismail Khan is the second serious attack of its kind in the town. Earlier this year, another police station in the town was also attacked by a few suicide attackers, during which some 20 policemen were held hostage by the attackers who later killed themselves or got killed after hours of firing with the security forces coming to rescue the hostages.