Singapore says it hopes all parties in Thailand will exercise restraint and work towards restoring peace and order.

"As a friend of Thailand, we follow closely the latest developments in Thailand with concern. We hope that all parties involved will exercise restraint and work towards restoring peace and order in accordance with Thailand's constitutional process and laws,'' Singapore's Ministry of Foreign Affairs said in a statement on Tuesday night.

"Thailand is an important regional country and its stability is crucial to the region as a whole. We hope that the situation will return to normal as soon as possible," it added.

Singapore's comments come as the Thai military imposed martial law nationwide on Tuesday, after months of violent anti-government protests.