Tensions continue to rise over new travel document showing vast portions of South China Sea as Chinese territory.

The Philippines has become the latest country to say it will not stamp visas in the new Chinese passport because it contains a map showing parts of the South China Sea, claimed by the Philippines, as Chinese territory.

The Philippines will instead issue a seperate visa form for Chinese nationals holding the controversial passport, according to the foreign ministry.

The Filipino government said that this move reinforces its protest about claims over the western Philippine Sea. It also argued that stamping the passport could be "misconstrued" as "legitimising" China's claims. The foreign secretary, Albert del Rosario, sent Beijing a formal protest letter last week, calling the passport maps "an excessive declaration of maritime space in violation of international law".

The new Chinese passport contains a map that suggests a Chinese claim over vast parts of the South China Sea, which are also claimed in part by the Philippines, Vietnam, Brunei, Malaysia and Taiwan.

Vietnam has also refused to stamp the passports, while Taiwan has objected to the map's maritime borders. India, angered that the map claims their state of Arunachal Pradesh and the Aksai China as Chinese territory, is issuing Chinese citizens visas embossed with New Delhi's own version of the map.