Pakistan has suspended mobile phone services in major cities, a move officials say is necessary to prevent terror attacks from marring Shia Muslim processions.
"All the blasts that occurred within the last 15 days were mobile-phone based," Interior Minister Rehman Malik told reporters on Friday.
Mobile and wireless phone services were temporarily blocked in the commercial capital Karachi, the southwestern city of Quetta and in parts of the capital.
The Pakistan Telecommunications Authority (PTA) said the suspension was likely to continue until Ashura, the climax of the month of Muharram, on Sunday.
"The wireless phone service will most likely be suspended for the next two days just the way it was today," Akhlaq Hussain, a director of PTA, told AFP.
Interior Minister Rehman Malik announced the phone suspension earlier, saying it was intended to "ensure security during and after the Muharram processions".
Malik said he had received a request from the government in Punjab province, Pakistan's most populous, to suspend mobile phone communications in 14 cities for two days.
Mobile phone services in various parts of the northwest, south and Pakistan-controlled Kashmir will also be suspended, he added.
It is the second time Pakistan has shut down mobile networks during the holy month of Muharram, which culminates with Ashura, the holiest day in the Shia Muslim calendar when faithful march to mourn the seventh-century killing of Imam Hussein.
A suicide bomber killed 23 people and wounded 62 others at a Shia procession in Rawalpindi on Thursday, the deadliest bombing in Pakistan for five months.
In December 2009, a suicide bomber killed 43 people in Karachi at a Shia procession to mark Ashura.
Pakistan says 35,000 people have been killed as a result of terrorism since the 9/11 attacks and the 2001 US-led invasion of neighbouring Afghanistan.