In Bangladesh, police have increased efforts to identify those responsible for hundreds of small, coordinated blasts that hit across the country. Wednesday's blasts have raised concerns about the security situation in the country.
A day after a series of blasts hit virtually every district of Bangladesh, police have detained nearly 100 people for questioning.
There was no immediate breakthrough in the case, but officials say the investigation is going well. Police say they are probing a possible link to a banned Islamic group, Jamaat-ul Mujahedin. Leaflets bearing the group's name and calling for Islamic rule in the country were found at some of the blast locations.
At least two people died in the explosions and more than 100 were hurt.
Wednesday's blasts were the latest in a series of bombings that have hit targets such as opposition political rallies, shrines and cinemas.
But security analysts point out a crucial difference - the latest blasts, though small, were conducted on a scale never seen before.
A security expert, former Brigadier General Sakhawat Hossain in Dhaka says the countrywide, synchronized explosions highlight what he calls a delicate national security situation.
"Whosoever has done it, they must have sent a message to the government that government is not very effective in checking what has been happening in last few years," he said. "If they could do it simultaneously in the whole of the country that definitely talks [says] that the government apparatus has not been up to the mark."
In the past year India has expressed concern about the rising influence of Islamic militants in Bangladesh. In February, a South Asian summit to be held in Dhaka was postponed after New Delhi refused to attend because of security concerns following a grenade attack on an opposition rally.
Independent political analysts say several small, militant Islamic groups have sprung up in Bangladesh in recent years, mostly in the impoverished northern and southern regions.
In February, the government banned the Jamaat-ul-Mujahidin and another group for their alleged role in a series of killings, robberies and other violent incidents. The ban was seen as a major policy change for a government that had long insisted the country faces no threat from Islamic militancy.
Experts such as Mr. Hossain say there is surprise that any group in the country had the ability to conduct the kind of strike seen Wednesday.
"There could be some small group, but should that small group become so big and so powerful, in that case I would say that our system has not worked, or our system is not adequate to check on to all this," he said. "Unless we wake up now, we could get into a serious problem."
Newspaper editorials called for the government, the opposition, and the rest of the country to unite and root out those responsible.
Political analysts say Bangladesh's population, almost entirely Muslim, is mostly moderate, and committed to the country's secular democracy.