MINSK (Reuters) - Belarusian security forces detained protesters and fired water cannon to disperse crowds as thousands took to the streets of Minsk against the abrupt inauguration of veteran President Alexander Lukashenko on Wednesday. Ignoring calls for an end to his 26-year grip on power, Lukashenko was sworn in for a sixth term after an election that the opposition and several foreign governments say was rigged. The ceremony would normally have been publicised as a major state occasion but was instead held without warning following Lukashenko’s claim of a landslide victory in the Aug. 9 vote. The former Soviet republic’s opposition, which has staged more than six weeks of mass protests demanding his resignation, denounced the inauguration as illegitimate. “His secret inauguration is an attempt to seize power,” said Sviatlana Tsikhanouskaya, Lukashenko’s main opponent who fled into exile after the election.The United States and the European Union are drawing up sanctions against officials involved in the election and a subsequent crackdown on protesters by the security forces. Lukashenko placed his right hand on a copy of the constitution and swore the oath of office at a ceremony attended by several hundred people. The 66-year-old leader said the country needed safety and consensus “on the brink of a global crisis”, an apparent reference to the COVID-19 pandemic. “I cannot, I have no right to abandon the Belarusians,” he said.Thousands of protesters marched through the streets carrying red-and-white opposition flags, as passing cars honked their horns in solidarity. One placard read “if you have 80%, why are you afraid of us?” - alluding to Lukashenko’s stated 80% vote share. Protesters formed human chains to block off some streets and caused traffic snarls. Occasional scuffles broke out as demonstrators tried to stop others getting detained. Local media footage showed helmeted riot police pinning protesters to the ground, and marching or carrying them away into detention.Several people were injured after water cannon were fired, the Russian news agency Interfax reported. More than 10 people had been taken into custody, the official Belta news agency said, while the human rights group Spring 96 said it was at least 116. The government typically releases the final figure the following day. Protesters had begun gathering in small groups in the capital earlier in the day, including outside at least three universities, local media footage showed. Some chanted “Sasha, come out, we’ll congratulate you!” - referring to the diminutive form of Lukashenko’s first name.Rumours had swept Minsk that Lukashenko was preparing for a snap inauguration ceremony when a motorcade swept through the centre of the capital. Another opposition politician, Pavel Latushko, said the swearing-in was like a secret “thieves’ meeting”. “Where are the jubilant citizens? Where is the diplomatic corps?” he posted on social media. “It is obvious that Alexander Lukashenko is exclusively the president of the OMON (riot police) and a handful of lying officials.” Latushko called for “an indefinite action of civil disobedience”. Slideshow ( 5 images ) “SUCH A FARCE” Germany reiterated that it did not recognise Lukashenko as president and called for EU sanctions to be agreed as soon as possible. Lithuanian Foreign Minister Linas Linkevicius said on Twitter: “Such a farce. Forget elections...His illegitimacy is a fact with all the consequences that this entails.” Lukashenko, taking the oath for a new five-year term, promised to “faithfully serve the people of the Republic of Belarus, respect and protect the rights and freedoms of the person and of the citizen” and defend the constitution.He has so far withstood the protests with backing from his ally, President Vladimir Putin of Russia. Despite its population of only 9.5 million, Belarus matters to Russia as a buffer state against NATO and a conduit for Russian exports of oil and gas. At a summit last week, Putin granted Lukashenko a $1.5 billion loan, and the two countries are holding “Slavic Brotherhood” defence exercises in Belarus. As part of those drills, Russian paratroopers parachuted into Belarus on Wednesday. Kremlin spokesman Dmitry Peskov said the swearing-in was “absolutely the sovereign decision of the Belarusian leadership”. Additional reporting by Matthias Williams in Kyiv, Vladimir Soldatkin in Moscow and Andrius Sytas in Vilnius, Writing by Mark Trevelyan and Matthias Williams; Editing by John Stonestreet, Mark Heinrich and Jonathan Oatis