Two senior U.N. inspectors tasked with examining claims that chemical weapons have been deployed in Syria's civil war arrived in Damascus on Wednesday, an Agence France Presse photographer reported.

Swedish scientist Ake Sellstrom and Angela Kane, the U.N. high representative for disarmament, arrived at a hotel in the Syrian capital.

A blast Wednesday at a police station in a Nile Delta city killed one person and wounded 28, a medic said, in the latest incidence of violence sweeping Egypt since president Mohammed Morsi's ouster.

Mohamed Sultan, deputy head of the emergency services, told Agence France Presse an explosive device went off very early in the morning outside a police station in the city of Mansura, in Dahqaliya province.

Two rockets fired from the Gaza Strip hit southern Israel on Wednesday but caused no damage or casualties, a police spokeswoman said.

"The rockets landed in the Eshkol region," Luba Samri told Agence France Presse, adding that "security forces are searching for their remains".

Militants killed nine police in an attack with mortars and automatic weapons in Iraq on Wednesday, while 14 people including six soldiers died in other violence, officers and doctors said.

The attacks come a day after an al-Qaida front group claimed brazen assaults on two prisons in Iraq that killed more than 40 people, among them 20 members of the security forces, and saw hundreds of inmates, including senior militants, escape.

Gas-rich Qatar, a strong backer of Arab Spring uprisings and supporter of ousted Egyptian president Mohammed Morsi, has joined international calls for his release from detention while expressing concern at violence sweeping Egypt.

State news agency QNA late Tuesday quoted a foreign ministry official as saying Qatar had voiced "concern over the developments in Egypt, especially with the increasing number of civilian victims.”

Syria's opposition leader is scheduled to meet French President Francois Hollande Wednesday, a day after asking France for military aid to boost the forces fighting the regime of President Bashar Assad.

"This is one of the goals of our visit among other issues," new opposition chief Ahmad Jarba told reporters after meeting members of the French parliament's foreign affairs committee on Tuesday at the start of a two-day trip.

U.N. hopes of investigating chemical weapon attacks in Syria suffered a blow when rebels seized a key town, diplomats said ahead of talks starting Wednesday.

Opposition fighters took Khan al-Assal from President Bashar Assad's forces two days ahead of the arrival in Damascus of Ake Sellstrom, head of a U.N. inquiry into the use of chemical arms in the 28-month-old conflict, and U.N. disarmament affairs chief Angela Kane.

Bombs targeting worshipers gathered for evening prayers at three Sunni mosques in Iraq killed nine people on Tuesday, officials said.

A bomb exploded in the Omar bin Abdulaziz Mosqe in the northern city of Kiruk, while another blast struck near Al-Salihin Mosque close by, killing a total of seven people and wounding 41.

Yemeni authorities on Tuesday released a journalist who had been detained for three years on charges of promoting al-Qaida, the state news agency Saba reported.

Investigative journalist Abdul Ilah Haydar Shae was arrested on August 16, 2010 on charges of links to al-Qaida and sentenced the following years to five years in prison.

Senior aides held with ousted president Mohammed Morsi since Egypt's army toppled him nearly three weeks ago have asked their families for prison clothes, signalling possible charges, relatives said Tuesday.

Khaled El-Qazzaz, the former president's secretary for foreign relations, and top adviser Essam El-Haddad made the request in telephone conversations last Friday, their relatives told Agence France Presse.