A suicide blast went off at a busy intersection in the Syrian capital Friday, killing 25 people and wounding at least 46 others.

Syrian state media say an attacker blew himself up near a school and police station in the central district of Midan in Damascus.

A bus carrying policemen appeared to be the target of the attack.

State television showed people carrying human remains, and others shouting the blast was the work of terrorists. The footage also showed damaged vehicles, including what appears to be a police bus with shattered windows and blood in it.

The government and opposition have traded accusations about who orchestrated the blast.

A leader of the opposition Free Syrian Army told al-Arabiya TV the Syrian government has a “long history of manipulating terrorist attacks.”

Syria has long accused armed terrorists of driving the uprising against the regime of President Bashar al-Assad.

In Washington, State Department spokeswoman Victoria Nuland condemned the attack. She said that as with previous attacks, Syria had blamed “just about everybody” — the opposition, al-Qaeda and even the United States. She declined to speculate who might be responsible for the attack.

The attack came two weeks after twin blasts targeting security buildings in Damascus killed 44 people.

Meanwhile, there is mounting criticism about the effectiveness of an Arab League mission in Syria that is monitoring President Bashar al-Assad's compliance with a plan to end a 10-month crackdown on protesters.

On Thursday, Qatar's prime minister admitted the Arab League mission has made mistakes.

The Arab League will meet in Egypt on Sunday to assess the mission's findings in Syria and decide whether it will continue.

The Arab League effort is aimed at ensuring Mr. Assad follows through on his pledge to withdraw security forces from cities, release political prisoners and allow anti-government demonstrations.

The United Nations estimates that 5,000 people have died since the uprising began in March. But the global activist group Avaaz says nearly 7,000 people have been killed in the Syrian unrest.