Karachi tense after fatal clashes

Paramilitary troops are out in force in the Pakistani city of Karachi, with tension high a day after ethnic clashes killed at least 24 people.
There have been a number of fresh incidents of violence reported, including shots fired at the funerals of some of the victims.
The clashes are said to be between Urdu-speakers and ethnic Pashtuns.
Separately, President Asif Ali Zardari called for national unity in tackling militants in the restive north-west.
Pakistani troops this week launched operations in the Lower Dir and Buner regions to remove Taleban militants who had spread there from their stronghold in Swat.
Obama's concern
In Karachi, a spokesman from the Pakistan Rangers paramilitary force told Reuters news agency: "We have heavy deployment of troops across the city, and they have been told to go to any extent to control the situation, including shoot at sight orders for miscreants."
See a map of the north-west region
Shots were fired by unidentified gunmen at funerals being held in North Karachi on Thursday and clashes were reported in at least two other areas of the city.
About 25 people have been arrested in connection with Wednesday's shootings.
There is reduced public transport and schools are closed.
Karachi has a history of ethnic violence.

The clashes were said to be between Urdu-speakers and ethnic Pashtuns
It is dominated by Urdu-speakers, but there is also a growing population of ethnic Pashtuns.
Officials said Wednesday's fighting was between members of the two groups, and started after an unidentified man opened fire, killing three members of the Urdu-speaking Muttahida Qaumi Movement (MQM).
Most of the dead in the violence were Pashtuns.
Police said that 16 cars, 20 shops and eight hotels were set on fire on Wednesday.
In the north-west, the military is continuing its operations in Buner, less than 100km (60 miles) from the capital, Islamabad.
On Wednesday it said it had taken control of the key town of Dagar.
The army said hundreds of Taleban fighters had spread to Buner after a peace deal.
The peace deal sets up Sharia law in parts of the region in return for an end to the Taleban insurgency.
However, the Taleban have not laid down their arms.
The army says fighting in Lower Dir has ended.
On Wednesday, Mr Zardari said Pakistan was facing a "critical hour" in tackling the militants.
"The time has come for the entire nation to give pause to their political differences and rise to the occasion and give full support to our security forces," a presidential statement said.
Also on Wednesday, US President Barack Obama again said he was "gravely concerned about the situation in Pakistan".
"I'm more concerned that the civilian government there right now is very fragile," he said.link...