From an old BBC news report:

Monkeys invade Delhi government

Tuesday, 9 January, 2001,
14:38 GMT

Thousands of monkeys are invading government buildings in Delhi, forcing employees to arm themselves
with sticks and stones in case they are attacked.

    At least 10,000 monkeys are creating havoc in the Indian capital by barging into government offices, stealing food, threatening bureaucrats and even ripping apart valuable documents.

    The increasingly aggressive animals swing effortlessly between the offices of the defence, finance and external affairs ministries and some have even been spotted in the prime minister’s office.

    “They are moving in very high security areas,” says Defence Ministry officer, IK Jha.

    Officials say there is little that can be done.

    Killing the animals is not an option because monkeys are a sacred symbol in Hinduism, India’s main religion.

    The authorities used to capture the monkeys and ship them to neighbouring states, but this is no longer possible because other areas are now being over populated with monkeys.

    The government held a high-level meeting two years ago to solve the problem permanently.

    Suggestions ranged from setting up a separate park for captured monkeys to “monkey contraception.”

    Nothing has been done since then and employees still walk to work in fear of attack.
    
“I am sometimes faced with groups of monkeys, big huge looking fellows,” says government employee Surekha Rao. “What I do is make some noise with my shoes so the monkey moves away.”

    Animal rights activists say the main problem is not the rising number of monkeys but the growing population of humans.

    “We have encroached on their homelands, we have taken away their fruits, we have reduced their water sources and we are trapping them from their home range, from their forests, so they are coming to urban areas,” says rights activist Iqbal Malik.