Kashmir: Why is the region disputed and so sensitive?

Tensions between India and Pakistan have escalated after the killing of 25 Indian tourists and a Nepalese citizen in the disputed Himalayan Kashmir region on Tuesday, prompting warnings of a return to conflict.

- Peter Beaumont

Why is Kashmir so sensitive?

The region in the foothills of the Himalayas has been disputed since India and Pakistan came into being in 1947. Both claim it in full, but each controls a section of the territory, separated by one of the world's most heavily militarised borders: the "line of control" based on a ceasefire border established after a 1947-48 war. China controls another part in the east.

India and Pakistan have gone to war a further two times over Kashmir, most recently in 1999.

The dispute stems from the partition of colonial India in 1947, when small, semi-autonomous "princely states" across the subcontinent were being folded into India or Pakistan, and the local ruler chose to become part of India despite the fact the area had a Muslim majority.

Armed insurgents in Kashmir have resisted New Delhi for decades, with many Muslim Kashmiris supporting the rebels' goal of uniting the territory either under Pakistani rule or as an independent country. India accuses Pakistan of backing militants - a claim Pakistan denies.

What has happened in recent years that has contributed to current tensions?