( Reuter )- Two suicide car bombers struck in the Pakistani city of Lahore on Tuesday, killing 24 people and wounding scores, most of them in an attack on a government security office, police and officials said.
More than 500 people have been killed in Pakistan this year in militant-related violence, including a campaign of suicide bombings.
One bomb went off near the entrance of the city-centre Federal Investigation Agency (FIA), badly damaging the multi-storey office and nearby buildings. The agency focuses on illegal immigration and people smuggling.
"It is now more obvious that the terrorists are targeting the law enforcement apparatus of the state," city police chief Malik Mohammad Iqbal told reporters.
The blasts came as opposition parties that won a February 18 election were forming a coalition government, raising hopes for political stability after months of turmoil over opposition to President Pervez Musharraf.
Interior Ministry spokesman Javed Iqbal Cheema said the bomber at the FIA building killed 21 people, 12 of them agency staff.
At about the same time, a second suicide bomber in a car struck in a mainly residential neighborhood of the eastern city, about 10 km (six miles) away, killing three people including two children, he said.
In all, 170 people were wounded, he said.
"We're going through a very crucial phase of transition," Cheema told a news conference, referring to the new government.
"Perhaps one answer could be that the terrorists are trying to put maximum pressure on the government that is in the making," he said.
Last week, a twin-suicide bombing killed five people in an attack on a navy college in Lahore.
Police said the second car bomb blew up after it was stopped at the gate of an advertising agency office, near the Lahore home of Asif Ali Zardari, the widower of assassinated former prime minister Benazir Bhutto.
Zardari, who led Bhutto's party to election victory last month, said this week the party would not flinch from a long fight against militancy. He was in Islamabad on Tuesday.
Provincial governments had been asked to review security plans and accelerate intelligence gathering to try to stop bombers before they strike, Cheema said.
"Unfortunately our enemy is nameless, faceless," Cheema said, adding that bombers worked in small groups or even alone.
Pakistani stocks fell in early trade after the Lahore bombs heightened concerns about deteriorating security, but the main index ended slightly higher on bargain hunting, dealers said.
Musharraf condemned the blasts.
"Acts of terrorism cannot deter the government's resolve to fight the scourge with full force," the state news agency quoted him as saying.
In New York, U.N. Secretary-General Ban Ki-moon condemned the attacks and sent his condolences to the victims' families, his spokeswoman Michel Montas said.
"The secretary-general is concerned by the increase of terrorist attacks in Pakistan over the past few months and welcomes the resolve of the government and people of Pakistan to unite against the scourge of terrorism," she said.
Pakistan has been battling Islamist militancy since joining the U.S.-led campaign against terrorism after the September 11, 2001, attacks on the United States.
While much of the violence has taken place in remote northwestern regions, suicide attacks have taken place in all of Pakistan's major cities over the past year.
In a separate incident, three suspected militants were killed in an army artillery attack on their hideout in the Swat Valley in North West Frontier Province, police said.
Also on Tuesday, cricket officials said Australia had postponed their planned tour of Pakistan because of security fears.