Gunmen in Nigeria have abducted at least eight people from a hospital in the north-west of the country, police say.
The attack took place at the National Tuberculosis and Leprosy Centre in Zaria early on Sunday morning.
Reports say the number of people taken by the group is higher and includes nurses and children.
There has been a recent spate of abductions from schools and universities for ransom.
Police said the gunmen, thought to be from criminal groups known locally as "bandits", opened fire on a police station in the city.
While they were engaged in the shootout, another group attacked the hospital.
"The attack on the police station was a distraction whilst another group attacked the dormitories of the health centre workers," a local resident told AFP news agency.
The group escaped with the victims into a nearby forest.
A hospital worker, who asked not to be named, told BBC Hausa that the gunmen had abducted at least 12 people, including three children under the age of three and a teenager.
A local government official said troops were stepping up efforts to find the victims.
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Kidnappings are common across the country.
Last February, nearly 300 schoolchildren were abducted from a school in Zamfara state.
Authorities say recent attacks on schools in the north-west have been carried out by bandits, a loose term for kidnappers, armed robbers, cattle rustlers and other armed militia operating in the region who are largely motivated by money.
Since the well-publicised abduction in 2014 of 276 schoolgirls from Chibok secondary school by Boko Haram Islamist militants in Borno state, more armed groups have resorted to mass abduction of students.
media captionNigeria child abduction: Kidnappers demand millions for a child's lifeNo end in sight to wave of kidnappings
Analysis by Mayeni Jones, BBC News, Lagos
Once again the northern state of Kaduna finds itself in the eye of Nigeria's kidnapping storm.
This latest attack is shocking in that it reportedly involves three infants, but this is not the first time a hospital has been targeted.
In late April, armed gunmen took two female nurses from a hospital in Kajuru area of Kaduna state. Schools and universities in the state have also been repeatedly targeted by kidnappers since March.
The state governor told the BBC that he believes kidnappers have come to Kaduna from other states, because he's been vocal about his decision not to engage with kidnappers in any way.
But now even Governor Nasir El Rufai has succumbed to pressure from the kidnappers – he recently withdrew his son from a local school where he had enrolled him to promote confidence in public schools. He told the BBC that he'd decided to take his son out to protect other pupils. This latest move will embolden his critics who say his tough stance is counter-productive.
But kidnappings continue to take place, both in states where governors engage with kidnappers, and in states where they don't.
With few economic prospects for many young Nigerians, and with security forces struggling to stop the wave of abductions, it's hard to see how this kidnapping crisis will stop.