Kinshasa - Opposition campaigners launched a two-day general strike on Tuesday to pressure Democratic Republic of Congo President Joseph Kabila to set an election date - a day after 12 people were shot dead in an anti-government rampage in the capital.The "dead city" action in Kinshasa, organised well before Monday's killings, was to turn up the heat on Kabila, who is still in power despite his mandate expiring last year.Business activity was noticeably slower in the morning after the opposition had called on residents to stay home.Two-thirds of shops and banks were closed, AFP journalists reported, as soldiers and police were out in strength to monitor the situation."Everything is closed. The city is paralysed," a city resident, Kiki Kalombo, told AFP."It's to make Corneille Nangaa put out a calendar for the elections," he added, referring to the head of the Independent National Electoral Commission (CENI).Nangaa has already stated that they cannot organise a presidential poll as anticipated by year's end.The government meanwhile has written to mobile phone operators, calling on them to limit the "abusive" use of social media, in what appeared to be a bid to stop photos being posted of the protests which were also taking place in other cities.At Lubumbashi, a regional capital in the southeast of the Democratic Republic of Congo, the main fish market was closed after youths clashed with the security forces. Elsewhere in the city, however, it was business as usual.And in Goma, the capital of North Kivu province in the country's restive east, riot police were posted at all main junctions in the city, an AFP correspondent said. A few dozen youths using rocks tried to barricade some streets.Anti-Kabila rampage Police say Monday's killings came as the anti-Kabila Bundu Dia Mayala group went on a rampage, attacking the security forces in several neighbourhoods around Kinshasa. Members of the group, sporting red bandanas, had sprung their attack while chanting "prayers and slogans hostile to legally established institutions," said police spokesperson Pierrot Rombaut Mwanamputu on Monday.The victims were hit by stray bullets, he added.But while many citizens of Kinshasa backed Tuesday's strike, not everyone was happy."The 'dead city' policy has never come up with the hoped-for results," said Alexander, owner of a fish store."My business is shut. I've lost clients. The economy is on its knees," he said.In his eyes, a strongman was needed to force out Kabila, who came to power in 2001 after the assassination of his father, Laurent Kabila.The political instability in the vast country of 70 million in the heart of Africa has raised concerns in the international community, and a top UN official in Kinshasa on Monday met with the government to discuss ways to move rapidly toward elections. Kasai bloodshed Ahead of this week's protests, Prime Minister Bruno Tshibala insisted on Saturday that the country was "on course" for elections.But he failed to give the opposition the detailed timeline they have been demanding for months.One of the main obstacles to organising polls was the continuing violence in the central, diamond-rich region of Kasai where a rebellion has been going on for a year now, according to the electoral commission chief.Both the government and rebels have been accused of carrying out atrocities in Kasai and the international community has repeatedly expressed concern at the government's handling of dissent.Only last week, the UN's peacekeeping mission in DRC known as MONUSCO voiced alarm at "arbitrary arrests" during a protest against Kabila.And just a few days later a UN report detailed more than 250 "extrajudicial or targeted killings" of civilians in Kasai earlier this year, with dozens of children among the victims.Detailing cases of people being burned alive or mutilated, the report blamed government troops as well as militia groups on both sides of the conflict.