Maiduguri -Nigeria on Wednesday re-imposed a telephone blackout on many parts of Nigeria's northeast Borno state, the base of Boko Haram Islamists who have intensified attacks that has claimed scores of lives, the army said.
"GSM (Global System for Mobile Communication) services have been seized in Borno again and this is one of the sacrifices that people have to make," army spokesman Colonel Muhammad Dole said.
"There is an ongoing operation and we want to get it right. We are hopeful GSM services would be restored soon," he said without giving details.
Phone services which were frozen last May until December in Borno, Adamawa and Yobe after the government imposed a state of emergency.
Most people woke up on Wednesday and found out they could no longer make calls on their mobile phones, residents said.
Dole said residents in the area had to be patient.
"In the ongoing operation we have reached a stage whereby the cooperation of everybody is necessary in order to subdue the common enemy," Dole said.
He thanked the youth vigilantes, also known as civilian JTF (Joint Task Force) for their "unprecedented support to the military" in the ongoing offensive against Islamists.
The youths provide the military with information on Boko Haram.
Some residents in Maiduguri, Borno's state capital, said if the phone cut would restore law and order, then they backed the move. But one local, Kabiru Sani, a trader, doubted if the measure would achieve the desired goal.
"When they seized the GSM network last year, the terrorists were not perturbed, they kept killing people. GSM services were only restored when the terrorists attacked military bases in December," he said.
Another trader, Umar Babagana, said the decision to freeze phone services was "retrogressive" and "a serious setback".
"For how long would Nigeria be using crude method to track offenders?," he asked.
Borno on Tuesday began a three-day fasting and prayer period to end the blood-letting.
More than 1,000 people have been killed in the northeast since last May, despite an enhanced military presence.
Violence by Boko Haram militants has raged since 2009, claiming thousands of lives but has been particularly ferocious in recent weeks, with some 500 people killed in suspected Islamist attacks since the start of the year.
Worst hit by militant attacks are villages in remote, rural areas near Borno's border with Cameroon, despite an increased military presence in the state.
On February 25, at least 43 students were shot and hacked to death in their dormitory when suspected Boko Haram gunmen stormed the Federal Government College in Buni Yadi, in nearby Yobe state.