Thailand's junta vowed to tighten security on Monday after two homemade pipe bombs detonated near a Bangkok shopping mall, the first major disruption to an uneasy peace imposed under martial law since May's coup.

Authorities declined to speculate whether the small bombs - which caused minor injuries to two passers-by when they exploded near the Siam Paragon mall on Sunday evening - were linked to the nation's turbulent politics.

Deputy Prime Minister Prawit Wongsuwon warned that the public will now face increased security. "We will strictly enforce security across the country. We need to have high security checks in some areas," he told reporters.