Syria Rebel
A member of the Free Syrian Army aims his weapon as an unknown car approaches towards his position in the outskirts of Taftanaz village, east of Idlib city April 12, 2012. Reuters/Stringer

Syria's ceasefire was in peril Sunday as the government vowed a crackdown on a wave of terrorist attacks and its forces shelled Homs on the day the first U.N. peace monitors were due to arrive.

An initial team of U.N. ceasefire monitors was due to land Sunday evening and will be deployed on Monday in an effort to keep the peace plan on track, the spokesman for international mediator Kofi Annan said.

The Syrian government said it could not be responsible for the safety of the monitors unless it is involved in all steps on the ground, government spokeswoman and presidential adviser Bouthaina Shaaban said.

She also said the number of monitors could rise to 250, but that Syria reserved the right to agree on their nationality.

British Foreign Secretary William Hague said the 30 unarmed observers who have been sanctioned to enter Syria by a unanimous vote at the Security Council on Saturday were insufficient and had to be beefed up, Reuters reported.

This number of people cannot possibly effectively monitor what is happening in the whole country, he said in an interview with Sky News, adding that 30 monitors could, however, quickly visit areas where there are reports of ceasefire breaches.

The six, to be followed immediately by another 25 to 30 military observers drawn from United Nations missions in the region, will be ready to begin patrols as early as Monday if the Syrian government cooperates, Ahmad Fawzi, spokesman for Annan, told the New York Times. That advance team, small for a country the size of Syria, is due to grow to 250 after further negotiations with Damascus.

But four days after a ceasefire was meant to come into effect, violence persists.

Early this morning we saw a helicopter and a spotter plane fly overhead. Ten minutes later, there was heavy shelling, Walid al-Fares, an activist living in the battered Homs district of Khalidiya, told Reuters.

Activist video footage, reportedly from Khalidiya, shows an explosion shortly after the sound of a missile flying through the air. Another whiz follows, and the cameraman, standing in a nearby building, pans across to show a ball of flames and smoke rising into the air.

Rami Abdelrahman, head of the British-based Syrian Observatory for Human Rights, said shells were being fired at a rate of one a minute.

People said they heard explosions and shooting after rebels attacked a police station and then clashed with police, he said.

In the north, government forces were randomly shelling the village of Khirbet Jouz, aiming at a group of fighters from the Free Syrian Army there, said the Local Coordination Committee, an activist group.

In response, the Syrian government warned that armed terrorist groups have intensified attacks with the ceasefire. A military official quoted by state television said security forces will prevent the terrorist groups from continuing their criminal attacks, the Voice of America reported

Syria blames the violence on terrorists seeking to topple President Bashar al-Assad and has repeatedly denied journalists access to the country, making it impossible to independently verify the reports.

Meanwhile, a German-owned ship was halted after its owners received information that it might be carrying weapons bound for Syria, Bloomberg Businessweek reported, citing Der Spiegel. The agent for the company chartering the ship vehemently denied that it was carrying any such load.

Germany has been a strong advocate of sanctions against Syria. The European Union has imposed an arms embargo among other measures, and the German government said it was looking into the report.

Der Spiegel reported that the Atlantic Cruiser was stopped in the Mediterranean after its owners were warned it was suspected to be carrying Iranian military equipment to Tartus, Syria. Without citing sources, it said defectors in the Syrian government apparatus were behind the alert.

Der Spiegel quoted shipping agent Torsten Lueddeke of Hamburg-based C.E.G. Bulk Chartering as saying: We stopped the ship after we received information on the weapons cargo.

He said the ship had been chartered to an Odessa, Ukraine-based company called White Whale Shipping and they declared to us as cargo above all pumps and things like that, according to the report. We would never have allowed weapons on board.

Varamar, the general agent for White Whale Shipping, called the accusations groundless.

The ship was waiting at sea for further instructions. Cyprus Foreign Minister Erato Kozakou-Marcoullis told her country's state television late Saturday said that the ship was 40 to 50 nautical miles off the eastern coast of Cyprus, and that authorities were monitoring it.

Although violence has continued throughout the ceasefire, there has been a significant drop in the daily death toll in fighting which has often killed more than 100 people a day.

On Saturday, 14 people were killed in the violence, Abdelrahman said. The state news agency SANA said armed terrorists killed five people in ambushes around the country.

The U.N. vote on Saturday was the first Security Council resolution on Syria the 15-nation council has managed to approve unanimously since the uprising erupted in March 2011.

Russia and China have previously blocked Western attempts to pass Security Council resolutions on Syria.

The Arab League, which along with the United Nations backed the negotiations by Annan leading to the declaration of a ceasefire, welcomed the Security Council decision to send in monitors.

The Arab League welcomes this decision as it represents an international will to support the mission of the joint envoy Kofi Annan, Egypt's news agency MENA said, quoting deputy Arab League chief Ahmed Ben Helli.

Helli said Annan will report on his mission at an Arab League meeting on Syria on Tuesday in Qatar.

I will make sure that this advance observer mission will be dispatched as soon as possible and try to make concrete proposals by the 18th of April for an official observer mission, U.N. Secretary-General Ban Ki-moon told United Nations radio in Geneva.

Abu Rabea, an opposition activist in Homs, dismissed the ceasefire and the monitoring mission.

Nothing has changed in Homs. Government loyalists on roofs are using heavy machine guns to shoot us and we are being shelled. The only thing that has changed is that Kofi Annan's plan is said to be accepted by the regime and the world believes them.

The Security Council resolution condemned the widespread violations of human rights by the Syrian authorities, as well as any human rights abuses by armed groups.

The text included a vague warning to Damascus, saying the council would assess the implementation of this resolution and to consider further steps as appropriate.

U.S. Ambassador to the United Nations Susan Rice condemned what she said was Syria's murderous rampage over the last year. Asked if Syrian government shelling of Homs on Saturday was a violation of the ceasefire, Rice said: Absolutely.

The U.N. estimates Assad's forces have killed more than 9,000 people in the uprising. Syrian authorities say foreign-backed militants have killed more than 2,500 soldiers and police.