Taliban insurgents stormed the justice ministry in Kabul on Wednesday, killing two government employees, while two suicide bombers attacked another government building in north Kabul, police and witnesses said.

The incidents come at a time of worsening security in the country and a day before Richard Holbrooke, the new U.S. special envoy to Afghanistan and Pakistan, was expected to visit Kabul.

A private television station quoted a Taliban spokesman as saying seven of its fighters were trying to attack the justice ministry and a prison department office building in revenge for the treatment of jailed insurgents.

Five of the Taliban insurgents who entered the justice ministry were would-be suicide bombers, two were shot dead by security forces, two were in the basement, and another would-be bomber was on a top floor of the building, a policeman told Reuters.

Another official told Reuters security forces had so far shot dead four insurgents who were attempting to blow themselves up.

"During the operations, four terrorists were killed inside the justice ministry. Our operations still continue," Zemarai Bashary, interior ministry spokesman said, adding he had no further details about casualties.

"Security forces rescued us. I saw the bodies of two (would-be) suicide bombers, perhaps more of them are being held up. Officials are still being held inside," said a justice ministry official, who did not want to be named, standing outside the ministry.

Constant gunfire could be heard outside the ministry as police scaled the building using ladders to try and enter from its top floor windows, a Reuters witness said.

A justice ministry employee, Sazul Rahman, said he saw three suicide bombers enter the ministry near the presidential palace. One shot dead a security guard while the others fired at employees as they went through the building.

The area around the presidential palace is tightly guarded and home to foreign embassies and government buildings. Residents said hundreds of shops had closed.

Hundreds of people were seen fleeing in panic and sirens were heard in Kabul.

In the north Kabul suburb of Khair Khana, two suicide bombers blew themselves up inside a government prisons department, while a third would-be bomber escaped, a policeman at the scene said.

Another official said there were casualties from the blasts, but had no details on figures of killed or wounded.

A spokesman for the Taliban claimed responsibility for the attacks.

Separately, four Afghan army soldiers were killed on Wednesday when a roadside bomb hit their vehicle during an operation in Logar province to the south of Kabul, provincial spokesman, Deen Mohammad Darwesh told reporters.

The Taliban, ousted in a U.S.-led invasion in 2001, have made a comeback in recent years, and carried out a series of high-profile attacks in Kabul last year.

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