Local media reported that as many as 10 police officers had been shot in the standoff, and television stations broadcast footage of bloodied officers being carried on stretchers from the scene.

The total number of hostages, some of whom are believed to be citizens of Western nations, was not known. Neither was the number of the attackers, or their identities.

“We are requesting the ones who are inside the restaurant to talk to us, relay us your demands,” said Benazir Ahmed, the director general of the Rapid Action Battalion, the country’s counterterrorism force, according to The Dhaka Tribune.

The United States State Department alerted American citizens in the area to the reports of the attack, and advised them to “shelter in place and monitor news.”