A suicide bomber killed at least 70 people and wounded dozens in an attack that struck a gathering of Pakistani lawyers on the grounds of a government-run hospital in the southwestern city of Quetta on Monday, police said. Witnesses described horrifying scenes of bodies being scattered about and the wounded screaming out and crying for help. No group immediately claimed responsibility for the blast. Nearly 100 lawyers had come to the hospital in the heart of Quetta, the capital of Baluchistan province, after the body of their colleague, prominent attorney Bilal Kasi was brought there. Kasi was shot and killed by gunmen earlier on Monday, as he was on his way to his office, and the lawyers later gathered at the Quetta Civil Hospital to express their grief. "It was a suicide attack," said Zahoor Ahmed Afridi, a senior police officer. Afridi said the attacker hit shortly after Kasi's body was brought in and that it seemed the two events were connected. Noor Ahmed, the hospital's deputy chief surgeon for victims of violent crime, said they were treating about 50 wounded in the bombing. "I can confirm that so far, 53 people have been killed in today's bombing at our hospital," said Ahmed. One of those who survived the bombing described a horrifying scene, saying there were "bodies everywhere" after the blast. Waliur Rehman said he was taking his ailing father to the emergency ward when the explosion shook the building. The blast was so powerful that they both fell down, he said. When he looked up, Rehman said he saw bodies of the dead and the wounding crying out for help. He was about 200 meters (yards) away from where the bombing struck, he added. Another witness, lawyer Abdul Latif, said he arrived at the hospital to express his grief over Kasi's killing. But he said he didn't know he would "see the bodies of dozens of other lawyers" killed and wounded shortly after arriving. Sanaullah Zehri, chief minister in Baluchistan province, said both the bombing and Kasi's slaying seemed to be part of a plot to disrupt peace in the provincial capital. Sarfraz Bugti, the provincial interior minister, denounced the attack as an "act of terrorism." A Pakistani news channel reported that one of its cameramen was also killed in the blast. Local TV stations broadcast footage showing people running in panic around the hospital grounds. Afridi said most of the dead were lawyers who had gathered after Kasi's body was brought to the hospital. Prime Minister Nawaz Sharif strongly condemned the blast and expressed his "deep grief and anguish over the loss of precious human lives" in the attack, in which several senior lawyers were also killed. "No one will be allowed to disturb the peace in the province that has been restored thanks to the countless sacrifices by the security forces, police and the people of Baluchistan," he said in a statement. Sharif asked the local authorities to maintain utmost vigilance and beef up security in Quetta. He also instructed health officials to provide the best treatment possible to those wounded in the attack. Gen. Raheel Sharif, the powerful army chief of Pakistan, visited the Quetta Civil Hospital, and met with those wounded in the attack. Ali Zafar, the head of the country's main association of lawyers, condemned the blast as "an attack on justice." He said lawyers will observe three days of mourning and will not appear in court in solidarity with their colleagues and others killed in the attack. Quetta and the rest of Baluchistan province have long been hit by insurgency. There are several ethnic Baluch separatist groups operating in the resource-rich province, but al-Qaida and other militant groups also have a presence here.