Islamabad, Pakistan (CNN) -- At least three gunmen have kidnapped two foreign aid workers in Punjab Province in central Pakistan, police said Friday.
The aid workers, one German and one Italian, had just returned to their home Thursday in Multan after helping victims of the 2010 flood in the outskirts of the city when the gunmen forced their way inside, said Muhammad Iqbal, a police official.
The kidnapping took place inside a military cantonment, an enclosed community that houses mostly military offices but some civilian homes.
Security is usually high in cantonments and residents can only come and go by showing their identification at security check posts. Iqbal says it is not clear how the kidnappers managed to get by at least three check posts and reach their victims' home.
The two aid workers had not notified authorities that they were working and living in the cantonment as required by Pakistani law, Iqbal said.
No one has claimed responsibility for the kidnapping, police say.
The kidnapping of foreigners is a growing trend in Pakistan.
Last year, al Qaeda claimed responsibility for the kidnapping of American aid worker Warren Weinstein in Lahore and a Swiss couple in Balochistan. But most of the kidnappings are done by criminal gangs looking to make money by demanding a ransom, authorities say.