Lome - Thousands of people protested in Togo on Wednesday in the next phase of a campaign to force out President Faure Gnassingbe, whose dynasty has ruled the West African state for more than 50 years.Marchers converged along three routes in the capital of Lome to a seafront site where they were to be addressed by opposition leaders, AFP reporters saw.Mobile access to the internet was cut, as was the case in mass protests against Gnassingbe in August and September that drew tens of thousands of people."We are going to maintain pressure," said Jean-Pierre Fabre, president of the main opposition party, the National Alliance for Change (ANC)."We are demanding the return to [Togo's] 1992 constitution, with all the outcomes from this which follow," he said during the march, referring to the crux of the protesters' demands.The government, responding to unprecedented protests from the street, is proposing an overhaul of the constitution under which presidential terms would be limited to two five-year spells in office.Gnassingbe, in power since the death of his father in 2005, was re-elected in 2010 and again in 2015, in votes that the opposition denounced as unfair. If the two-term limit applies from the next elections, scheduled in 2020, he could theoretically remain in office until 2030.As a result, the opposition wants the two-term restriction to be applied retroactively by restoring the 1992 constitution, in order to force Gnassingbe from office.At least four people were killed and dozens were injured in September in a crackdown in the north of the country, a region previously seen as reliably pro-government.'Final warning'Thousands turned out in the north on Wednesday, including the towns of Bafilo and Sokode, where youths blockaded Highway 1, the country's only north-south axis, local residents said.Wednesday's protests were billed by the 14-party opposition coalition last week as a "final warning" to the regime.They are scheduled to be followed on Thursday by more rallies, described as a "march of anger."The president's father, General Gnassingbe Eyadema, ruled the country with an iron fist from 1967 until his death in 2005.Transparency International ranked Togo 116th out of 176 countries in its annual corruption Perceptions Index last year.Togo was 166th out of 188 countries in the UN Development Programme's human development report, which looks at areas such as levels of income, health and education.