Lashkar-e-Jhangvi founder Malik Ishaq was picked up by police from his home late on Tuesday, said police officer Mohammad Ibrahim.

Ibrahim said Ishaq was not charged, but detained under a public order act. This means he can be kept for three months.

Since his release on bail in July, Ishaq made several speeches that appeared to advocate violence against Shiite Muslims.

Ibrahim said the detention order was ordered to stop Khan making speeches “harmful for peace and harmony.”

Ishaq was accused in dozens of killings, including many of minority Shiites, but freed because the Supreme Court decided there wasn’t enough evidence to keep holding him. His case never went to trial.

Laskar-e-Jhangvi is one of Pakistan’s most notorious groups, with thousands of supporters in the country’s most populous province, Punjab. It is formally banned by the government, but has managed to keep operating. Its members have been linked to Al-Qaeda and many of the terrorist attacks to hit the country over the last four years.

As other Sunni extremist groups like Al-Qaeda and the Taleban, it regards Shiite Muslims as nonbelievers and liable to be killed. Many hundreds of Shiites have been killed in bomb and gun attacks in Pakistan.