Why has China sent research vessels to Scarborough Shoal after a collision?
The presence of two survey ships, one equipped with drones, may be a sign Beijing is looking to step up monitoring at the flashpoint

The Xiang Yang Hong 10, an ocean research vessel operated by China’s Ministry of Natural Resources, has been operating near the reef since last Friday, according to information from the satellite-based Automatic Identification System.
As of Tuesday evening, both vessels remained south of the shoal and close to each other, according to the satellite information from open source tracking website vesselfinder.com
Meanwhile, the Philippine coastguard vessel BRP Cape San Agustin was patrolling east of the shoal on Friday and Saturday, returning again on Monday.
Scarborough Shoal has become one of the main flashpoints in the two countries’ long-running dispute over the South China Sea.