BEIRUT: Mortar shells struck a residential area in central Damascus Wednesday, killing three people and wounding more than 50, including a number of women and children, state-run news agency said.

The latest mortar attacks came as Syrian government troops fought fierce battles with rebels for control of key neighborhoods in the northeast of the capital, residents and activists said.

SANA said "terrorists" targeted the al-Boukhtyar neighborhood of Damascus with mortars and that two of the mortar shells struck near an orphanage. The Syrian government refers to rebels fighting to topple President Bashar Assad as terrorists.

Rebels have stepped up mortar attacks on Damascus in recent weeks, striking deeper than ever into the heart of the city in a new tactic to try and loosen Assad's grip on his main stronghold.

The pro-government Al-Ekhbariya TV aired footage of the attacks, showing houses and cars on fire and firefighters working to extinguish the flames. People were shown weeping and cursing the rebels.

Also, a European Union staff member was killed in a rocket attack on an opposition stronghold south of the capital, the EU said.

Opposition fighters have been trying to advance into Damascus for weeks, battering regime checkpoints and military bases in the heavily fortified capital.

Both sides see Damascus as the ultimate prize in the civil war.

The Syrian Observatory for Human Rights said Wednesday's clashes were concentrated in the capital's neighborhoods of Jobar and Barzeh.

A resident in the area said shelling overnight "shook apartments" and terrified the inhabitants. He spoke on condition of anonymity because he feared for his safety.

A car bomb exploded outside a police station in Khan Sheih neighborhood, west of Damascus, the Observatory said. The Britain-based activist group also said fierce clashes broke out after the blast but had no immediate reports of casualties.

Fighting also raged in other Syrian cities, including Homs, where the military pounded rebel positions with artillery and carried out several airstrikes on the Baba Amr district, a former rebel stronghold which the opposition has tried to recapture in the past days.

In Brussels, EU foreign policy chief Catherine Ashton said a policy officer with the European delegation in Syria was killed on Tuesday in the Damascus suburb of Daraya. It was the first death of an EU employee in the Syrian civil war.

Ahmad Shihadeh, 32, worked for the EU for five years, a spokesman for Ashton said Wednesday. He said Shihadeh had lived in Daraya, a suburb of Damascus that has been one of the main battlefields in the capital.

Ashton said he "died while providing humanitarian help to the community of Daraya," Ashton said. "Ahmad was known for his courage and selflessness."

Ashton took the occasion to call for an end to the conflict, which started in March 2011 as protests against Assad's authoritarian rule. The revolt turned into civil war after some opposition supporters took up arms to fight back a harsh government crackdown on dissent.

"As we approach the second anniversary of the uprising in Syria, I call again on all sides to take urgent steps to end the violence, which has led to the deaths of some 100,000 innocent citizens and over 1 million refugees seeking shelter in neighboring countries," she said.

According to U.N. figures, more than 70,000 people have been killed in the 2-year-old conflict and four millions Syrians driven from their homes. There was no immediate explanation of Aston's higher death toll.

Also Wednesday, a Ukrainian journalist who was kidnapped in Syria last year and escaped after being held by rebels for more than 150 days spoke of her ordeal to The Associated Press in Damascus.

Ankhar Kochneva said she was held by members of the Farouk Brigade of the Free Syrian Army in the central Homs province. She said in a phone interview that she "almost died" because of the shelling of the area she had been held, and that food was scarce while in captivity.

Kochneva wrote for Syrian and Russian newspapers before she was kidnapped in western Syria on Oct. 9. On Tuesday, Ukraine's Foreign Ministry confirmed that the journalist was freed.

In a phone interview Wednesday, the reporter told the AP she escaped from the house where she was being held while the guards were sleeping. She said she skirted a rebel guard post and fled with the assistance of villagers working in nearby fields.

She said no ransom was paid for her release.

"I would not want to buy my life, because they will by weapons with the money to kill civilians," she said.