BANGKOK: Thailand's military has charged four people with sedition after seizing T-shirts allegedly promoting republicanism, a legal aid group said Friday, the latest crackdown on political activism as the kingdom prepares for long-delayed elections. The arrests began September 6 when authorities found one woman in possession of 400 T-shirts promoting the "Thai Federation" movement that seeks to turn the constitutional monarchy into a republic, according to a representative from the Thai Lawyers for Human Rights group. Republicanism is a taboo topic in Thailand where even perceived criticism of the monarchy can lead to 15 years in prison under draconian lese majeste laws. Political activity has also been banned since a 2014 military coup deposed the civilian government and as the countdown begins for the kingdom's first election in four years, authorities have ramped up pressure on activists. Three of those arrested have been released on bail, according to a representative from the Thai Lawyers for Human Rights. "All four suspects are charged with sedition and illegal association," said lawyer Pawinee Chumsri. "These offences each carry a maximum prison term of seven years." The three released will be summoned to a court where a prosecutor will decide if they are to be indicted or freed. The Thai Federation movement has no on-the-ground presence in Thailand and appears to be mainly active online, with support from Thais living overseas. Deputy Prime Minister Prawit Wongsuwan said earlier this week the group is based in Laos and is affiliated with an activist who fled the country because of lese majeste charges. Prawit also played down the group's importance, saying that the group "doesn't carry any weight and they are just trying to incite people on social media to think of separatism to create a new republic." Human Rights Watch's Sunai Phasuk said he does not know much about the group, but since the suspects have not engaged in violence, their actions are considered "peaceful". "The government should exercise restraint and they should not be pressing serious charges against them like sedition," Sunai said. Defense Ministry spokesman Kongcheep Tantravanich said the authorities are investigating the Thai Federation's purpose and the people involved in it.