(CNN)Hong Kong's pro-democracy camp has endured a setback in crucial by-elections as fears grow that Beijing is tightening its grip on the semi-autonomous region.
Democrats won only two of four seats contested in the 70-seat Legislative Council and failed to regain their veto power in Sunday's vote, which was triggered when Beijing forced the disqualification of six lawmakers.
The election means that the pro-democracy camp now only holds 26 seats in the partially elected legislature, one short of being able to block bills.
"There was low voter turnout and the two pro-democracy candidates who won did so by a historically low margin," said Willy Lam, a professor at the Chinese University of Hong Kong.
"This reflects the popular feeling that President Xi Jinping is determined to squeeze Hong Kong and to go back on his early promises of allowing it autonomous powers," he added.
Turnout in the four constituencies that cast ballots was 43%, much lower than previous elections in 2016, when turnout was 58.3%.
The vote drew criticism from activists after a pro-democracy candidate, Agnes Chow, was barred from standing for election at the last minute. Authorities extended a blanket ban on pro-independence candidates to also include those who advocate self-determination for the city.
Her party, Demosisto, had advocated Hong Kongers be allowed to vote on the city's future when the one country, two systems arrangements run out in 2047.
Au Nok-hin, who replaced Chow as a candidate and won a seat for the pro-democracy camp on Hong Kong island, said that the result was a step forward, but told the South China Morning Post newspaper that it was "not a total victory."
He added that there had been little time to prepare for the election after Chow's disqualification.
Pro-Beijing parties hold a near unassailable majority in Hong Kong's legislature, LegCo, thanks to the functional constituency system, which allocates seats to certain business, trade and civil society groups, the majority of which take their lead from China.
Hong Kong under Xi
Sunday's vote came as China gave President Xi Jinping a mandate to rule for life, raising concerns for Hong Kong's freedoms.
Those fears were underscored on March 5, when a key report delivered by Premier Li Keqiang omitted the usual reference to the people of Hong Kong ruling themselves under the "one country, two systems" formula, which has governed the former British territory since its return to China in 1997.
The arrangement allows Hong Kong a degree of electoral freedom not enjoyed on the mainland, although Beijing ruled out universal suffrage for the city in 2014, sparking a huge street protest that became known as the Umbrella Movement.