DEVELOPING: Commandos backed by armored vehicles stormed a upscale restaurant in the Bangladesh's capital diplomatic zone early Saturday, hoping to free dozens of hostages held by Islamist militants following an hours-long standoff.
Approximately two hours after the operation began, the sound of two big explosions were heard inside the Dhaka restaurant and a police official told the Associated Press that five bodies were seen lying in pools of blood.
In Tokyo, Japan's Deputy Chief Cabinet Secretary Koichi Hagiuda, citing Dhaka police, said 12 people had been rescued, including two foreigners.
Local TV stations reported that the operation began at 7:40 a.m. local time (9:40 p.m. ET Friday). Local media reported that an Argentine and two Bangladeshis were rescued from the restaurant early Saturday, but details about their condition were not immediately available. Journalists were being kept away from the scene and authorities also ordered internet services to be blocked across the country, according to internet service provider Aamra.
The Islamic State (ISIS) group claimed responsibility for the attack on the Holey Artisan Bakery in Dhaka's Gulshan area, according to the SITE Intelligence Group, which monitors jihadist activity online.
Two police officers were killed and at least 26 people wounded in an earlier gunbattle as security forces cordoned off the area. At least 35 people, including about 20 foreigners, were still trapped inside the restaurant, said kitchen staffer Sumon Reza, who was among more than 10 people who managed to run to the rooftop and escape.
The attack marks an escalation in the growing drumbeat of militant violence to hit the traditionally moderate Muslim-majority nation in the past three years, but with increasing frequency in recent months. Most attacks have been by machete-wielding men singling out individual activists, foreigners and religious minorities.
Bangladesh did not immediately respond to the claim of responsibility by ISIS, but in the past have denied that the extremist group has a presence in the country. The U.S. State Department said it had seen the ISIS claim, but could not confirm its authenticity.
An ISIS-affiliated news agency claimed that 24 people had been killed and 40 wounded, including foreigners, according to SITE. The figures could not be independently confirmed.
The Amaq news agency also posted photos purportedly showing the bodies of hostages. The authenticity of the pictures could not be confirmed either.
Police said the two officers died at a hospital after being wounded in the gunfire with as many as nine attackers, who also hurled bombs. Ten of the 26 wounded were listed in critical condition, six of whom were on life support, according to hospital staff, who said the injuries ranged from broken bones to gunshot wounds. Only one civilian was among the wounded.
Reza said the attackers chanted "Allahu Akbar" (God is Great) as they launched the attack around 9:20 p.m. local time Friday, initially opening fire with blanks. A huge contingent of security forces cordoned off the area around the bakery.
Resident Lutful Amin told The Associated Press he heard several explosions, the last of which went off around 10:45 p.m.
Among the hostages was a businessman and his wife and two children, according to his uncle Anwarul Karim.
"My nephew Hasnat Karim called me and said he was inside with his family. He told me, `Please save us, please!' And he hung up," he said. "We do not know what is going on there."
In Washington, a White House official said President Barack Obama was briefed on the attack by his chief counterterrorism adviser Lisa Monaco. The president asked to be kept informed as the situation develops, said the official, who was not authorized to speak publicly about the president's meetings.
State Department spokesman John Kirby says the U.S. is in contact with the Bangladesh government and has offered its assistance to bring those responsible to justice.
He said all official American personnel are accounted for with no injuries reported, and the department is working with local authorities to determine if any U.S. citizens and locally-employed staff were affected.
The spree of recent attacks in Bangladesh have raised fears that religious extremists are gaining a foothold in the country, despite its traditions of secularism and tolerance.
About two dozen atheist writers, publishers, members of religious minorities, social activists and foreign aid workers have been slain since 2013. On Friday, a Hindu temple worker was hacked to death by at least three assailants in southwest Bangladesh. IS and and al-Qaida affiliates have claimed responsibility for many of the attacks.
Prime Minister Sheikh Hasina's government has cracked down on domestic radical Islamists. It has accused local terrorists and opposition political parties -- especially the main opposition Bangladesh Nationalist Party and its Islamist ally Jamaat-e-Islami -- of orchestrating the violence in order to destabilize the nation, which both parties deny.