A jail superintendent and 11 other officials were arrested in the wake of a jail break in which two militants who were on trial escaped from a high-security prison, a police official said Saturday.

The arrested officials were being questioned to determine how two members of the outlawed Lashkar-e-Jhangvi group escaped Wednesday from the jail in the port city of Karachi, senior police official Khawaja Naveed said.

He alleged the two men escaped due to negligence of the jail staff. Naveed said efforts were under way to trace and capture the escapees who were arrested in 2013 over alleged links to terrorism.

His comments came two days after counter-terrorism officials claimed the two militants shaved their beards in a court bathroom located on the jail premises and fled without being checked. Authorities conduct trials of high-profile militants inside jails due to security reasons.

Also on Saturday, Mohammad Saeed, provincial head of the paramilitary Rangers, said security forces in an overnight raid arrested four members of the Lashkar-e-Jhangvi group and seized weapons and explosives from their hideout in Karachi. He said the detained men wanted to target a rally of Shi'ite Muslims.

The arrest of the four men came as Shiites prepared to hold rallies across Pakistan to observe the death anniversary of Imam Ali, the father of Imam Hussain who was killed along with 72 friends and family members at the battle of Karbala in Iraq.

Lashkar-e-Jhangvi has links to the Pakistani Taliban and is accused of killing scores of minority Shiite Muslims in Pakistan.