LOMÉ, Togo — Tens of thousands of people in the small West African nation of Togo have protested in the streets over the last three months, demanding term limits and the resignation of President Faure Gnassingbé, whose family has been in power for five decades.

Toting banners of “Faure must go” and “50 years of dictatorship are enough,” protesters have demonstrated repeatedly across the nation, even as heavily armed security forces have been deployed. Some demonstrations have led to deadly, tear gas-filled clashes with officers firing live rounds and beating protesters.

In two marches last month, 11 protesters were killed, 44 wounded and 55 arrested, organizers of the demonstrations said at a news conference. The minister of security said no one had died and only six arrests were made.

During a protest in September in Mango, a city in northern Togo, a 9-year-old boy was shot dead, according to Amnesty International, which said about 25 people were injured. In August, two protesters were killed in Togo, according to the group.

The Gnassingbé family has been in power since 1967, when the current president’s father, Eyadéma Gnassingbé, seized power in a coup. He died in 2005, and his son succeeded him after an election whose results were contested. Hundreds died in protests before and after the election.

The campaigns in which Faure Gnassingbé was re-elected president in 2010 and 2015 were also marred by fraud accusations. The country’s Constitution allows Mr. Gnassingbé to stay in office indefinitely.

“I am 33 years old and have never experienced any other governance other than that of a Gnassingbé,” said Maxime Domegni, a Togolese journalist and activist.

Togo, which lies between Ghana and Benin, is one of the world’s poorest countries, with many people surviving on subsistence farming. About 60 percent of the nation’s population of 7.5 million is under the age of 25, and poor living conditions and unemployment among the nation’s youth are helping to fuel the demonstrations.

The protests, however, have resonated across age groups, social classes and ethnicities, drawing supporters from the north, where the president’s family is from, and the south. During the demonstrations, street hawkers have marched alongside intellectuals.

“Some believe that the protesters are only from lower social classes,” Mr. Domegni said. “Last time, I met my university teacher between the protesters. He was the dean of the law department. Many other university teachers were there as well.”

The organizing force behind the demonstrations is an opposition coalition of 14 parties, led by the Pan-African National Party.

Last month, a military raid in the northern city of Sokodé led to the detention of a well-known imam, Alfa Alassane, who is a close ally of the leader of the Pan-African National Party. Angered by the arrest, supporters of the opposition in several cities built makeshift barricades and started small fires in the city centers. Protesters have also set ablaze the homes of several members of the presidential party, the Union for the Republic.

“We will continue our struggle until the end,” Jean-Pierre Fabre, a key opposition figure and leader of the National Alliance for Change, told his supporters in September in Lomé, the nation’s capital, according to the BBC.

The leaders of the demonstrations say they want presidential term limits and elections that include two rounds of voting.

In an effort to appease the protesters, the Togolese Parliament voted in September to amend the Constitution to limit presidents to two terms. But the opposition boycotted the vote, fearing it would not apply retroactively to the current president and would allow him to run again in 2020. The change is required to be approved in a referendum before it can take effect.

Opposition members have used social media to distribute their messages, and a Twitter hashtag, #TogoDebout, or Togo Rising, has become popular.

The government of Togo has shut down the internet in the days before and during protests to try to limit their size, but with limited success, as tens of thousands have turned out.

“Togo has experienced smaller protests in recent years, but to reach this magnitude is nothing short of extraordinary,” said Farida Nabourema, the leader of a civic organization called the Togolese Civil League.

Ms. Nabourema said the recent demonstrations have been notable because they started in regions of Togo that are the traditional strongholds of the Gnassingbé family. Those areas have been neglected over time, currently making them some of the poorest in the country.

“We are witnessing an unprecedentedly unified movement between the Togolese in all areas of the country,” she said. Ms. Nabourema now lives in exile, after her statements against the president started angering those in power and led to increasing harassment, she said.

The United Nations High Commissioner for Refugees said that more than 500 Togolese have sought asylum in neighboring Ghana to escape the unrest.

Some analysts said the opposition movement could fizzle because its members have no clear goals.

But Isabelle Ameganvi, a prominent politician in the National Alliance for Change, said her party has plans for education, health and anti-corruption measures and hopes to claim the presidency in the future. Power in the nation, she said, must become more inclusive than it is now.

“No one party can rule this country,” she said. “It will require a strong coalition to lead Togo out of its deplorable current condition.”