A suicide bomber blew himself up outside a courthouse in northwestern Pakistan on Thursday, killing 19 people in the latest attack in an onslaught by Islamist militants retaliating against an army offensive near the Afghan border. The bombing was the seventh militant strike in less than two weeks in and around Peshawar, the largest city in the northwest. The attacks have killed more than 80 people. The bomber, who arrived in a taxi, was being searched by police officers at the gate of the city's lower court when he detonated explosives on his body, government official Sahibzada Anees said. Several damaged motorbikes were strewn about the site, on the main Khyber Road, and firefighters sprayed water on a charred, smoking white car. Dr. Saib Gul of the city's Lady Reading Hospital said 19 people, including three policemen, were killed and 51 were wounded. 'These attacks will not deter us in our fight against these beasts who are killing our children,' said Bashir Ahmad Bilour, senior minister of the North West Frontier Province. The army launched its offensive against the Pakistani Taliban in South Waziristan in mid-October. It has retaken many towns in the region, but the militants say they avoided fighting and will now begin a guerrilla campaign. The United States has welcomed the offensive, but wants the army to do more against the insurgents in the border area blamed for violence across the border in Afghanistan. Abdul Aziz, a restaurant owner in Peshawar, said business was down because of the rash of attacks but he expressed solidarity with the government's efforts. 'Today Peshawar is like a fort under attack ... each and every road and street of the city is barricaded and there's no more hustle-bustle at the bazaar,' he said. 'But after all these sacrifices, we want the government to end this menace of terrorism once and for all.' Pakistan officials flagged the offensive in South Waziristan several months before it actually began, which Bilour said allowed the militants to escape and plan the current wave of terror. 'Unfortunately the announcement of the operation in Waziristan prior to the actual operation caused this problem,' he said. 'They (the militants) are hiding in villages surrounding Peshawar and make their way in despite security.' Since the beginning of October, more than 300 people have been killed in bombings and militant raids on government, civilian and Western targets in the country, most of them in the northwest. Still, Prime Minister Yousuf Raza Gilani insisted most militant commanders were either killed or on the run. 'They are using the weapons they have scattered here and there,' he said. 'God willing, it will take some time, but I assure you things will return to normal soon.' The bomb explosion occurred hours after missiles fired from a suspected U.S. drone killed three suspected militants in Shana Khuwara village in North Waziristan, another region close to the Afghan border region where al-Qaida and Taliban hold sway. The missiles hit a house owned by a local tribesman just after midnight, two intelligence officials said on condition of anonymity because they were not authorized to talk to the media. Ahmed Noor Wazir, who witnessed the attack, said rescuers pulled three dead bodies and four badly wounded men from the rubble of the house, which was being used by Taliban militants. Shana Khuwara village is not far from the border with South Waziristan. Many militants are believed to have fled to North Waziristan to escape the fighting, which killed seven insurgents in the past 24 hours, the army said in a statement Thursday. The suspected drone strike was the third since Pakistan launched the offensive in mid-October. The pace of the attacks has slowed since the operation began, possibly to avoid the perception that the U.S. is aiding the Pakistani army with the strikes. Anti-American sentiment is pervasive throughout Pakistan, and the drone strikes are unpopular because they often kill innocent civilians. U.S. officials rarely discuss the missile strikes, and although Pakistan's government publicly condemns them as violations of its sovereignty, many analysts believe the two countries have a secret deal allowing them. ------ Associated Press writers Rasool Dawar in Mir Ali and Anwarullah Khan in Khar contributed to this report. 